context
stringlengths 545
71.9k
| questionsrc
stringlengths 16
10.2k
| question
stringlengths 11
563
|
|---|---|---|
what is an algorithm ? one definition might be a set of steps to accomplish a task . you might have an algorithm for getting from home to school , for making a grilled cheese sandwich , or for finding what you 're looking for in a grocery store . in computer science , an algorithm is a set of steps for a computer program to accomplish a task . algorithms put the science in computer science . and finding good algorithms and knowing when to apply them will allow you to write interesting and important programs . let 's talk about a few famous algorithms . how does google hangouts transmit live video across the internet so quickly ? they use audio and video compression algorithms . how does google maps figure out how to get from dallas , texas to orlando , florida so that you can get to disney world ? they use a route finding algorithm . how does pixar color a 3d model of a character based on the lighting in a virtual room ? they use a rendering algorithm . how does nasa choose how to arrange the solar panels on the international space station and when to rearrange them ? they use an optimization and a scheduling algorithm . those algorithms are more complex than our everyday algorithms like making a grilled cheese sandwich . but they boil down to the same thing , a set of steps to accomplish a task . if you know something about existing algorithms , you can save yourself some effort and make your programs faster by applying the right one . for example , let 's say that you 're writing a game and you want the user to be able to play against the computer . well , you could look at checkers games for inspiration . computer scientists have figured out how to write checkers programs that never lose by using the minimax search algorithm to search through the huge tree of possible moves . if your game is similar to checkers , then you might be able to use algorithms based on these techniques . if not , then knowing the limitations of those algorithms might lead you to redesign your game if it requires having a skilled computer player . it 's also important to know how to design new algorithms as well as how to analyze their correctness and efficiency . in the biological sciences , new algorithms are continually being designed with purposes like designing the molecular structures that are the core of disease fighting drugs . in physics , algorithms simulate climate and weather patterns . in other algorithms , search and analyze the vast data about stars in the universe that 's collected by automated space telescopes . across all the sciences , and even on websites like khan academy , efficient algorithms are needed to analyze huge data sets or to select intelligently from a vast number of possible decisions . in just about any area you might be interested , new algorithms will allow massive computational power to be harnessed to do things that people really need and care about . now , not all algorithms are created equal . so what makes a good algorithm ? the two most important criteria are that it solves a problem and that it does so efficiently . most of the time , we want an algorithm to give us an answer that we know is always correct . sometimes we can live with an algorithm that does n't give us the correct answer or the best answer because the only perfect algorithms that we know for those problems take a really , really long time . for example , let 's say we want a program that would determine the most efficient route for a truck that delivers packages , starting and ending the day at a depot . it would take weeks to run going through all the possibilities . but if we 're okay with a program that would determine a route that 's good but maybe not the best , then it could run in seconds . in some case , good is good enough . how do you measure the efficiency of an algorithm ? we could time how long it takes to run the code , but that would only tell us about that particular implementation in a certain programming language on a particular computer and just for the input it was given . instead , computer scientists use a technique called asymptotic analysis , which allows algorithms to be compared independently of a particular programming language or hardware so that we can conclusively say that yes , some algorithms are more efficient than others . now you can learn about algorithms and asymptotic analysis on khan academy thanks to the contribution of two dartmouth college professors . tom cormen is the first author of the most popular college algorithms textbook in the world , plus the author of algorithms unlocked . devin balkcom designed dartmouth 's intro cs course and researches robotics . he built the world 's first origami folding robot . tom and devin will teach you many of the algorithms that you would learn in apcs or cs 101 , like searching algorithms , sorting algorithms , recursive algorithms and my personal favorite , graph algorithms . there will be tons of interactive visualizations , quizzes and coding challenges to help you understand better along your learning journey .
|
what is an algorithm ? one definition might be a set of steps to accomplish a task .
|
can an algorithm be termed incorrect ?
|
what is an algorithm ? one definition might be a set of steps to accomplish a task . you might have an algorithm for getting from home to school , for making a grilled cheese sandwich , or for finding what you 're looking for in a grocery store . in computer science , an algorithm is a set of steps for a computer program to accomplish a task . algorithms put the science in computer science . and finding good algorithms and knowing when to apply them will allow you to write interesting and important programs . let 's talk about a few famous algorithms . how does google hangouts transmit live video across the internet so quickly ? they use audio and video compression algorithms . how does google maps figure out how to get from dallas , texas to orlando , florida so that you can get to disney world ? they use a route finding algorithm . how does pixar color a 3d model of a character based on the lighting in a virtual room ? they use a rendering algorithm . how does nasa choose how to arrange the solar panels on the international space station and when to rearrange them ? they use an optimization and a scheduling algorithm . those algorithms are more complex than our everyday algorithms like making a grilled cheese sandwich . but they boil down to the same thing , a set of steps to accomplish a task . if you know something about existing algorithms , you can save yourself some effort and make your programs faster by applying the right one . for example , let 's say that you 're writing a game and you want the user to be able to play against the computer . well , you could look at checkers games for inspiration . computer scientists have figured out how to write checkers programs that never lose by using the minimax search algorithm to search through the huge tree of possible moves . if your game is similar to checkers , then you might be able to use algorithms based on these techniques . if not , then knowing the limitations of those algorithms might lead you to redesign your game if it requires having a skilled computer player . it 's also important to know how to design new algorithms as well as how to analyze their correctness and efficiency . in the biological sciences , new algorithms are continually being designed with purposes like designing the molecular structures that are the core of disease fighting drugs . in physics , algorithms simulate climate and weather patterns . in other algorithms , search and analyze the vast data about stars in the universe that 's collected by automated space telescopes . across all the sciences , and even on websites like khan academy , efficient algorithms are needed to analyze huge data sets or to select intelligently from a vast number of possible decisions . in just about any area you might be interested , new algorithms will allow massive computational power to be harnessed to do things that people really need and care about . now , not all algorithms are created equal . so what makes a good algorithm ? the two most important criteria are that it solves a problem and that it does so efficiently . most of the time , we want an algorithm to give us an answer that we know is always correct . sometimes we can live with an algorithm that does n't give us the correct answer or the best answer because the only perfect algorithms that we know for those problems take a really , really long time . for example , let 's say we want a program that would determine the most efficient route for a truck that delivers packages , starting and ending the day at a depot . it would take weeks to run going through all the possibilities . but if we 're okay with a program that would determine a route that 's good but maybe not the best , then it could run in seconds . in some case , good is good enough . how do you measure the efficiency of an algorithm ? we could time how long it takes to run the code , but that would only tell us about that particular implementation in a certain programming language on a particular computer and just for the input it was given . instead , computer scientists use a technique called asymptotic analysis , which allows algorithms to be compared independently of a particular programming language or hardware so that we can conclusively say that yes , some algorithms are more efficient than others . now you can learn about algorithms and asymptotic analysis on khan academy thanks to the contribution of two dartmouth college professors . tom cormen is the first author of the most popular college algorithms textbook in the world , plus the author of algorithms unlocked . devin balkcom designed dartmouth 's intro cs course and researches robotics . he built the world 's first origami folding robot . tom and devin will teach you many of the algorithms that you would learn in apcs or cs 101 , like searching algorithms , sorting algorithms , recursive algorithms and my personal favorite , graph algorithms . there will be tons of interactive visualizations , quizzes and coding challenges to help you understand better along your learning journey .
|
what is an algorithm ? one definition might be a set of steps to accomplish a task .
|
is an algorithm like a routine ?
|
what is an algorithm ? one definition might be a set of steps to accomplish a task . you might have an algorithm for getting from home to school , for making a grilled cheese sandwich , or for finding what you 're looking for in a grocery store . in computer science , an algorithm is a set of steps for a computer program to accomplish a task . algorithms put the science in computer science . and finding good algorithms and knowing when to apply them will allow you to write interesting and important programs . let 's talk about a few famous algorithms . how does google hangouts transmit live video across the internet so quickly ? they use audio and video compression algorithms . how does google maps figure out how to get from dallas , texas to orlando , florida so that you can get to disney world ? they use a route finding algorithm . how does pixar color a 3d model of a character based on the lighting in a virtual room ? they use a rendering algorithm . how does nasa choose how to arrange the solar panels on the international space station and when to rearrange them ? they use an optimization and a scheduling algorithm . those algorithms are more complex than our everyday algorithms like making a grilled cheese sandwich . but they boil down to the same thing , a set of steps to accomplish a task . if you know something about existing algorithms , you can save yourself some effort and make your programs faster by applying the right one . for example , let 's say that you 're writing a game and you want the user to be able to play against the computer . well , you could look at checkers games for inspiration . computer scientists have figured out how to write checkers programs that never lose by using the minimax search algorithm to search through the huge tree of possible moves . if your game is similar to checkers , then you might be able to use algorithms based on these techniques . if not , then knowing the limitations of those algorithms might lead you to redesign your game if it requires having a skilled computer player . it 's also important to know how to design new algorithms as well as how to analyze their correctness and efficiency . in the biological sciences , new algorithms are continually being designed with purposes like designing the molecular structures that are the core of disease fighting drugs . in physics , algorithms simulate climate and weather patterns . in other algorithms , search and analyze the vast data about stars in the universe that 's collected by automated space telescopes . across all the sciences , and even on websites like khan academy , efficient algorithms are needed to analyze huge data sets or to select intelligently from a vast number of possible decisions . in just about any area you might be interested , new algorithms will allow massive computational power to be harnessed to do things that people really need and care about . now , not all algorithms are created equal . so what makes a good algorithm ? the two most important criteria are that it solves a problem and that it does so efficiently . most of the time , we want an algorithm to give us an answer that we know is always correct . sometimes we can live with an algorithm that does n't give us the correct answer or the best answer because the only perfect algorithms that we know for those problems take a really , really long time . for example , let 's say we want a program that would determine the most efficient route for a truck that delivers packages , starting and ending the day at a depot . it would take weeks to run going through all the possibilities . but if we 're okay with a program that would determine a route that 's good but maybe not the best , then it could run in seconds . in some case , good is good enough . how do you measure the efficiency of an algorithm ? we could time how long it takes to run the code , but that would only tell us about that particular implementation in a certain programming language on a particular computer and just for the input it was given . instead , computer scientists use a technique called asymptotic analysis , which allows algorithms to be compared independently of a particular programming language or hardware so that we can conclusively say that yes , some algorithms are more efficient than others . now you can learn about algorithms and asymptotic analysis on khan academy thanks to the contribution of two dartmouth college professors . tom cormen is the first author of the most popular college algorithms textbook in the world , plus the author of algorithms unlocked . devin balkcom designed dartmouth 's intro cs course and researches robotics . he built the world 's first origami folding robot . tom and devin will teach you many of the algorithms that you would learn in apcs or cs 101 , like searching algorithms , sorting algorithms , recursive algorithms and my personal favorite , graph algorithms . there will be tons of interactive visualizations , quizzes and coding challenges to help you understand better along your learning journey .
|
how do you measure the efficiency of an algorithm ? we could time how long it takes to run the code , but that would only tell us about that particular implementation in a certain programming language on a particular computer and just for the input it was given . instead , computer scientists use a technique called asymptotic analysis , which allows algorithms to be compared independently of a particular programming language or hardware so that we can conclusively say that yes , some algorithms are more efficient than others . now you can learn about algorithms and asymptotic analysis on khan academy thanks to the contribution of two dartmouth college professors .
|
what is the difference between container and panel in java programming ?
|
what is an algorithm ? one definition might be a set of steps to accomplish a task . you might have an algorithm for getting from home to school , for making a grilled cheese sandwich , or for finding what you 're looking for in a grocery store . in computer science , an algorithm is a set of steps for a computer program to accomplish a task . algorithms put the science in computer science . and finding good algorithms and knowing when to apply them will allow you to write interesting and important programs . let 's talk about a few famous algorithms . how does google hangouts transmit live video across the internet so quickly ? they use audio and video compression algorithms . how does google maps figure out how to get from dallas , texas to orlando , florida so that you can get to disney world ? they use a route finding algorithm . how does pixar color a 3d model of a character based on the lighting in a virtual room ? they use a rendering algorithm . how does nasa choose how to arrange the solar panels on the international space station and when to rearrange them ? they use an optimization and a scheduling algorithm . those algorithms are more complex than our everyday algorithms like making a grilled cheese sandwich . but they boil down to the same thing , a set of steps to accomplish a task . if you know something about existing algorithms , you can save yourself some effort and make your programs faster by applying the right one . for example , let 's say that you 're writing a game and you want the user to be able to play against the computer . well , you could look at checkers games for inspiration . computer scientists have figured out how to write checkers programs that never lose by using the minimax search algorithm to search through the huge tree of possible moves . if your game is similar to checkers , then you might be able to use algorithms based on these techniques . if not , then knowing the limitations of those algorithms might lead you to redesign your game if it requires having a skilled computer player . it 's also important to know how to design new algorithms as well as how to analyze their correctness and efficiency . in the biological sciences , new algorithms are continually being designed with purposes like designing the molecular structures that are the core of disease fighting drugs . in physics , algorithms simulate climate and weather patterns . in other algorithms , search and analyze the vast data about stars in the universe that 's collected by automated space telescopes . across all the sciences , and even on websites like khan academy , efficient algorithms are needed to analyze huge data sets or to select intelligently from a vast number of possible decisions . in just about any area you might be interested , new algorithms will allow massive computational power to be harnessed to do things that people really need and care about . now , not all algorithms are created equal . so what makes a good algorithm ? the two most important criteria are that it solves a problem and that it does so efficiently . most of the time , we want an algorithm to give us an answer that we know is always correct . sometimes we can live with an algorithm that does n't give us the correct answer or the best answer because the only perfect algorithms that we know for those problems take a really , really long time . for example , let 's say we want a program that would determine the most efficient route for a truck that delivers packages , starting and ending the day at a depot . it would take weeks to run going through all the possibilities . but if we 're okay with a program that would determine a route that 's good but maybe not the best , then it could run in seconds . in some case , good is good enough . how do you measure the efficiency of an algorithm ? we could time how long it takes to run the code , but that would only tell us about that particular implementation in a certain programming language on a particular computer and just for the input it was given . instead , computer scientists use a technique called asymptotic analysis , which allows algorithms to be compared independently of a particular programming language or hardware so that we can conclusively say that yes , some algorithms are more efficient than others . now you can learn about algorithms and asymptotic analysis on khan academy thanks to the contribution of two dartmouth college professors . tom cormen is the first author of the most popular college algorithms textbook in the world , plus the author of algorithms unlocked . devin balkcom designed dartmouth 's intro cs course and researches robotics . he built the world 's first origami folding robot . tom and devin will teach you many of the algorithms that you would learn in apcs or cs 101 , like searching algorithms , sorting algorithms , recursive algorithms and my personal favorite , graph algorithms . there will be tons of interactive visualizations , quizzes and coding challenges to help you understand better along your learning journey .
|
what is an algorithm ? one definition might be a set of steps to accomplish a task .
|
how long does it usually take until a person knows how to write complex algorithm ?
|
what is an algorithm ? one definition might be a set of steps to accomplish a task . you might have an algorithm for getting from home to school , for making a grilled cheese sandwich , or for finding what you 're looking for in a grocery store . in computer science , an algorithm is a set of steps for a computer program to accomplish a task . algorithms put the science in computer science . and finding good algorithms and knowing when to apply them will allow you to write interesting and important programs . let 's talk about a few famous algorithms . how does google hangouts transmit live video across the internet so quickly ? they use audio and video compression algorithms . how does google maps figure out how to get from dallas , texas to orlando , florida so that you can get to disney world ? they use a route finding algorithm . how does pixar color a 3d model of a character based on the lighting in a virtual room ? they use a rendering algorithm . how does nasa choose how to arrange the solar panels on the international space station and when to rearrange them ? they use an optimization and a scheduling algorithm . those algorithms are more complex than our everyday algorithms like making a grilled cheese sandwich . but they boil down to the same thing , a set of steps to accomplish a task . if you know something about existing algorithms , you can save yourself some effort and make your programs faster by applying the right one . for example , let 's say that you 're writing a game and you want the user to be able to play against the computer . well , you could look at checkers games for inspiration . computer scientists have figured out how to write checkers programs that never lose by using the minimax search algorithm to search through the huge tree of possible moves . if your game is similar to checkers , then you might be able to use algorithms based on these techniques . if not , then knowing the limitations of those algorithms might lead you to redesign your game if it requires having a skilled computer player . it 's also important to know how to design new algorithms as well as how to analyze their correctness and efficiency . in the biological sciences , new algorithms are continually being designed with purposes like designing the molecular structures that are the core of disease fighting drugs . in physics , algorithms simulate climate and weather patterns . in other algorithms , search and analyze the vast data about stars in the universe that 's collected by automated space telescopes . across all the sciences , and even on websites like khan academy , efficient algorithms are needed to analyze huge data sets or to select intelligently from a vast number of possible decisions . in just about any area you might be interested , new algorithms will allow massive computational power to be harnessed to do things that people really need and care about . now , not all algorithms are created equal . so what makes a good algorithm ? the two most important criteria are that it solves a problem and that it does so efficiently . most of the time , we want an algorithm to give us an answer that we know is always correct . sometimes we can live with an algorithm that does n't give us the correct answer or the best answer because the only perfect algorithms that we know for those problems take a really , really long time . for example , let 's say we want a program that would determine the most efficient route for a truck that delivers packages , starting and ending the day at a depot . it would take weeks to run going through all the possibilities . but if we 're okay with a program that would determine a route that 's good but maybe not the best , then it could run in seconds . in some case , good is good enough . how do you measure the efficiency of an algorithm ? we could time how long it takes to run the code , but that would only tell us about that particular implementation in a certain programming language on a particular computer and just for the input it was given . instead , computer scientists use a technique called asymptotic analysis , which allows algorithms to be compared independently of a particular programming language or hardware so that we can conclusively say that yes , some algorithms are more efficient than others . now you can learn about algorithms and asymptotic analysis on khan academy thanks to the contribution of two dartmouth college professors . tom cormen is the first author of the most popular college algorithms textbook in the world , plus the author of algorithms unlocked . devin balkcom designed dartmouth 's intro cs course and researches robotics . he built the world 's first origami folding robot . tom and devin will teach you many of the algorithms that you would learn in apcs or cs 101 , like searching algorithms , sorting algorithms , recursive algorithms and my personal favorite , graph algorithms . there will be tons of interactive visualizations , quizzes and coding challenges to help you understand better along your learning journey .
|
instead , computer scientists use a technique called asymptotic analysis , which allows algorithms to be compared independently of a particular programming language or hardware so that we can conclusively say that yes , some algorithms are more efficient than others . now you can learn about algorithms and asymptotic analysis on khan academy thanks to the contribution of two dartmouth college professors . tom cormen is the first author of the most popular college algorithms textbook in the world , plus the author of algorithms unlocked .
|
is there a specific area of mathematics ( preferably on khan academy ) that i can go through to help me learn the proper math to fully understand how to reduce an algorithm down to asymptotic notation ?
|
what is an algorithm ? one definition might be a set of steps to accomplish a task . you might have an algorithm for getting from home to school , for making a grilled cheese sandwich , or for finding what you 're looking for in a grocery store . in computer science , an algorithm is a set of steps for a computer program to accomplish a task . algorithms put the science in computer science . and finding good algorithms and knowing when to apply them will allow you to write interesting and important programs . let 's talk about a few famous algorithms . how does google hangouts transmit live video across the internet so quickly ? they use audio and video compression algorithms . how does google maps figure out how to get from dallas , texas to orlando , florida so that you can get to disney world ? they use a route finding algorithm . how does pixar color a 3d model of a character based on the lighting in a virtual room ? they use a rendering algorithm . how does nasa choose how to arrange the solar panels on the international space station and when to rearrange them ? they use an optimization and a scheduling algorithm . those algorithms are more complex than our everyday algorithms like making a grilled cheese sandwich . but they boil down to the same thing , a set of steps to accomplish a task . if you know something about existing algorithms , you can save yourself some effort and make your programs faster by applying the right one . for example , let 's say that you 're writing a game and you want the user to be able to play against the computer . well , you could look at checkers games for inspiration . computer scientists have figured out how to write checkers programs that never lose by using the minimax search algorithm to search through the huge tree of possible moves . if your game is similar to checkers , then you might be able to use algorithms based on these techniques . if not , then knowing the limitations of those algorithms might lead you to redesign your game if it requires having a skilled computer player . it 's also important to know how to design new algorithms as well as how to analyze their correctness and efficiency . in the biological sciences , new algorithms are continually being designed with purposes like designing the molecular structures that are the core of disease fighting drugs . in physics , algorithms simulate climate and weather patterns . in other algorithms , search and analyze the vast data about stars in the universe that 's collected by automated space telescopes . across all the sciences , and even on websites like khan academy , efficient algorithms are needed to analyze huge data sets or to select intelligently from a vast number of possible decisions . in just about any area you might be interested , new algorithms will allow massive computational power to be harnessed to do things that people really need and care about . now , not all algorithms are created equal . so what makes a good algorithm ? the two most important criteria are that it solves a problem and that it does so efficiently . most of the time , we want an algorithm to give us an answer that we know is always correct . sometimes we can live with an algorithm that does n't give us the correct answer or the best answer because the only perfect algorithms that we know for those problems take a really , really long time . for example , let 's say we want a program that would determine the most efficient route for a truck that delivers packages , starting and ending the day at a depot . it would take weeks to run going through all the possibilities . but if we 're okay with a program that would determine a route that 's good but maybe not the best , then it could run in seconds . in some case , good is good enough . how do you measure the efficiency of an algorithm ? we could time how long it takes to run the code , but that would only tell us about that particular implementation in a certain programming language on a particular computer and just for the input it was given . instead , computer scientists use a technique called asymptotic analysis , which allows algorithms to be compared independently of a particular programming language or hardware so that we can conclusively say that yes , some algorithms are more efficient than others . now you can learn about algorithms and asymptotic analysis on khan academy thanks to the contribution of two dartmouth college professors . tom cormen is the first author of the most popular college algorithms textbook in the world , plus the author of algorithms unlocked . devin balkcom designed dartmouth 's intro cs course and researches robotics . he built the world 's first origami folding robot . tom and devin will teach you many of the algorithms that you would learn in apcs or cs 101 , like searching algorithms , sorting algorithms , recursive algorithms and my personal favorite , graph algorithms . there will be tons of interactive visualizations , quizzes and coding challenges to help you understand better along your learning journey .
|
he built the world 's first origami folding robot . tom and devin will teach you many of the algorithms that you would learn in apcs or cs 101 , like searching algorithms , sorting algorithms , recursive algorithms and my personal favorite , graph algorithms . there will be tons of interactive visualizations , quizzes and coding challenges to help you understand better along your learning journey .
|
is there any source to find such fundamental algorithms ?
|
what is an algorithm ? one definition might be a set of steps to accomplish a task . you might have an algorithm for getting from home to school , for making a grilled cheese sandwich , or for finding what you 're looking for in a grocery store . in computer science , an algorithm is a set of steps for a computer program to accomplish a task . algorithms put the science in computer science . and finding good algorithms and knowing when to apply them will allow you to write interesting and important programs . let 's talk about a few famous algorithms . how does google hangouts transmit live video across the internet so quickly ? they use audio and video compression algorithms . how does google maps figure out how to get from dallas , texas to orlando , florida so that you can get to disney world ? they use a route finding algorithm . how does pixar color a 3d model of a character based on the lighting in a virtual room ? they use a rendering algorithm . how does nasa choose how to arrange the solar panels on the international space station and when to rearrange them ? they use an optimization and a scheduling algorithm . those algorithms are more complex than our everyday algorithms like making a grilled cheese sandwich . but they boil down to the same thing , a set of steps to accomplish a task . if you know something about existing algorithms , you can save yourself some effort and make your programs faster by applying the right one . for example , let 's say that you 're writing a game and you want the user to be able to play against the computer . well , you could look at checkers games for inspiration . computer scientists have figured out how to write checkers programs that never lose by using the minimax search algorithm to search through the huge tree of possible moves . if your game is similar to checkers , then you might be able to use algorithms based on these techniques . if not , then knowing the limitations of those algorithms might lead you to redesign your game if it requires having a skilled computer player . it 's also important to know how to design new algorithms as well as how to analyze their correctness and efficiency . in the biological sciences , new algorithms are continually being designed with purposes like designing the molecular structures that are the core of disease fighting drugs . in physics , algorithms simulate climate and weather patterns . in other algorithms , search and analyze the vast data about stars in the universe that 's collected by automated space telescopes . across all the sciences , and even on websites like khan academy , efficient algorithms are needed to analyze huge data sets or to select intelligently from a vast number of possible decisions . in just about any area you might be interested , new algorithms will allow massive computational power to be harnessed to do things that people really need and care about . now , not all algorithms are created equal . so what makes a good algorithm ? the two most important criteria are that it solves a problem and that it does so efficiently . most of the time , we want an algorithm to give us an answer that we know is always correct . sometimes we can live with an algorithm that does n't give us the correct answer or the best answer because the only perfect algorithms that we know for those problems take a really , really long time . for example , let 's say we want a program that would determine the most efficient route for a truck that delivers packages , starting and ending the day at a depot . it would take weeks to run going through all the possibilities . but if we 're okay with a program that would determine a route that 's good but maybe not the best , then it could run in seconds . in some case , good is good enough . how do you measure the efficiency of an algorithm ? we could time how long it takes to run the code , but that would only tell us about that particular implementation in a certain programming language on a particular computer and just for the input it was given . instead , computer scientists use a technique called asymptotic analysis , which allows algorithms to be compared independently of a particular programming language or hardware so that we can conclusively say that yes , some algorithms are more efficient than others . now you can learn about algorithms and asymptotic analysis on khan academy thanks to the contribution of two dartmouth college professors . tom cormen is the first author of the most popular college algorithms textbook in the world , plus the author of algorithms unlocked . devin balkcom designed dartmouth 's intro cs course and researches robotics . he built the world 's first origami folding robot . tom and devin will teach you many of the algorithms that you would learn in apcs or cs 101 , like searching algorithms , sorting algorithms , recursive algorithms and my personal favorite , graph algorithms . there will be tons of interactive visualizations , quizzes and coding challenges to help you understand better along your learning journey .
|
what is an algorithm ? one definition might be a set of steps to accomplish a task .
|
how to figure out algorithm to solve a problem in dynamic situation ?
|
what is an algorithm ? one definition might be a set of steps to accomplish a task . you might have an algorithm for getting from home to school , for making a grilled cheese sandwich , or for finding what you 're looking for in a grocery store . in computer science , an algorithm is a set of steps for a computer program to accomplish a task . algorithms put the science in computer science . and finding good algorithms and knowing when to apply them will allow you to write interesting and important programs . let 's talk about a few famous algorithms . how does google hangouts transmit live video across the internet so quickly ? they use audio and video compression algorithms . how does google maps figure out how to get from dallas , texas to orlando , florida so that you can get to disney world ? they use a route finding algorithm . how does pixar color a 3d model of a character based on the lighting in a virtual room ? they use a rendering algorithm . how does nasa choose how to arrange the solar panels on the international space station and when to rearrange them ? they use an optimization and a scheduling algorithm . those algorithms are more complex than our everyday algorithms like making a grilled cheese sandwich . but they boil down to the same thing , a set of steps to accomplish a task . if you know something about existing algorithms , you can save yourself some effort and make your programs faster by applying the right one . for example , let 's say that you 're writing a game and you want the user to be able to play against the computer . well , you could look at checkers games for inspiration . computer scientists have figured out how to write checkers programs that never lose by using the minimax search algorithm to search through the huge tree of possible moves . if your game is similar to checkers , then you might be able to use algorithms based on these techniques . if not , then knowing the limitations of those algorithms might lead you to redesign your game if it requires having a skilled computer player . it 's also important to know how to design new algorithms as well as how to analyze their correctness and efficiency . in the biological sciences , new algorithms are continually being designed with purposes like designing the molecular structures that are the core of disease fighting drugs . in physics , algorithms simulate climate and weather patterns . in other algorithms , search and analyze the vast data about stars in the universe that 's collected by automated space telescopes . across all the sciences , and even on websites like khan academy , efficient algorithms are needed to analyze huge data sets or to select intelligently from a vast number of possible decisions . in just about any area you might be interested , new algorithms will allow massive computational power to be harnessed to do things that people really need and care about . now , not all algorithms are created equal . so what makes a good algorithm ? the two most important criteria are that it solves a problem and that it does so efficiently . most of the time , we want an algorithm to give us an answer that we know is always correct . sometimes we can live with an algorithm that does n't give us the correct answer or the best answer because the only perfect algorithms that we know for those problems take a really , really long time . for example , let 's say we want a program that would determine the most efficient route for a truck that delivers packages , starting and ending the day at a depot . it would take weeks to run going through all the possibilities . but if we 're okay with a program that would determine a route that 's good but maybe not the best , then it could run in seconds . in some case , good is good enough . how do you measure the efficiency of an algorithm ? we could time how long it takes to run the code , but that would only tell us about that particular implementation in a certain programming language on a particular computer and just for the input it was given . instead , computer scientists use a technique called asymptotic analysis , which allows algorithms to be compared independently of a particular programming language or hardware so that we can conclusively say that yes , some algorithms are more efficient than others . now you can learn about algorithms and asymptotic analysis on khan academy thanks to the contribution of two dartmouth college professors . tom cormen is the first author of the most popular college algorithms textbook in the world , plus the author of algorithms unlocked . devin balkcom designed dartmouth 's intro cs course and researches robotics . he built the world 's first origami folding robot . tom and devin will teach you many of the algorithms that you would learn in apcs or cs 101 , like searching algorithms , sorting algorithms , recursive algorithms and my personal favorite , graph algorithms . there will be tons of interactive visualizations , quizzes and coding challenges to help you understand better along your learning journey .
|
he built the world 's first origami folding robot . tom and devin will teach you many of the algorithms that you would learn in apcs or cs 101 , like searching algorithms , sorting algorithms , recursive algorithms and my personal favorite , graph algorithms . there will be tons of interactive visualizations , quizzes and coding challenges to help you understand better along your learning journey .
|
what kind of algorithms are being used on the job of a computer engineer ?
|
what is an algorithm ? one definition might be a set of steps to accomplish a task . you might have an algorithm for getting from home to school , for making a grilled cheese sandwich , or for finding what you 're looking for in a grocery store . in computer science , an algorithm is a set of steps for a computer program to accomplish a task . algorithms put the science in computer science . and finding good algorithms and knowing when to apply them will allow you to write interesting and important programs . let 's talk about a few famous algorithms . how does google hangouts transmit live video across the internet so quickly ? they use audio and video compression algorithms . how does google maps figure out how to get from dallas , texas to orlando , florida so that you can get to disney world ? they use a route finding algorithm . how does pixar color a 3d model of a character based on the lighting in a virtual room ? they use a rendering algorithm . how does nasa choose how to arrange the solar panels on the international space station and when to rearrange them ? they use an optimization and a scheduling algorithm . those algorithms are more complex than our everyday algorithms like making a grilled cheese sandwich . but they boil down to the same thing , a set of steps to accomplish a task . if you know something about existing algorithms , you can save yourself some effort and make your programs faster by applying the right one . for example , let 's say that you 're writing a game and you want the user to be able to play against the computer . well , you could look at checkers games for inspiration . computer scientists have figured out how to write checkers programs that never lose by using the minimax search algorithm to search through the huge tree of possible moves . if your game is similar to checkers , then you might be able to use algorithms based on these techniques . if not , then knowing the limitations of those algorithms might lead you to redesign your game if it requires having a skilled computer player . it 's also important to know how to design new algorithms as well as how to analyze their correctness and efficiency . in the biological sciences , new algorithms are continually being designed with purposes like designing the molecular structures that are the core of disease fighting drugs . in physics , algorithms simulate climate and weather patterns . in other algorithms , search and analyze the vast data about stars in the universe that 's collected by automated space telescopes . across all the sciences , and even on websites like khan academy , efficient algorithms are needed to analyze huge data sets or to select intelligently from a vast number of possible decisions . in just about any area you might be interested , new algorithms will allow massive computational power to be harnessed to do things that people really need and care about . now , not all algorithms are created equal . so what makes a good algorithm ? the two most important criteria are that it solves a problem and that it does so efficiently . most of the time , we want an algorithm to give us an answer that we know is always correct . sometimes we can live with an algorithm that does n't give us the correct answer or the best answer because the only perfect algorithms that we know for those problems take a really , really long time . for example , let 's say we want a program that would determine the most efficient route for a truck that delivers packages , starting and ending the day at a depot . it would take weeks to run going through all the possibilities . but if we 're okay with a program that would determine a route that 's good but maybe not the best , then it could run in seconds . in some case , good is good enough . how do you measure the efficiency of an algorithm ? we could time how long it takes to run the code , but that would only tell us about that particular implementation in a certain programming language on a particular computer and just for the input it was given . instead , computer scientists use a technique called asymptotic analysis , which allows algorithms to be compared independently of a particular programming language or hardware so that we can conclusively say that yes , some algorithms are more efficient than others . now you can learn about algorithms and asymptotic analysis on khan academy thanks to the contribution of two dartmouth college professors . tom cormen is the first author of the most popular college algorithms textbook in the world , plus the author of algorithms unlocked . devin balkcom designed dartmouth 's intro cs course and researches robotics . he built the world 's first origami folding robot . tom and devin will teach you many of the algorithms that you would learn in apcs or cs 101 , like searching algorithms , sorting algorithms , recursive algorithms and my personal favorite , graph algorithms . there will be tons of interactive visualizations , quizzes and coding challenges to help you understand better along your learning journey .
|
let 's talk about a few famous algorithms . how does google hangouts transmit live video across the internet so quickly ? they use audio and video compression algorithms .
|
how does the internet gather so much info about someone ?
|
what is an algorithm ? one definition might be a set of steps to accomplish a task . you might have an algorithm for getting from home to school , for making a grilled cheese sandwich , or for finding what you 're looking for in a grocery store . in computer science , an algorithm is a set of steps for a computer program to accomplish a task . algorithms put the science in computer science . and finding good algorithms and knowing when to apply them will allow you to write interesting and important programs . let 's talk about a few famous algorithms . how does google hangouts transmit live video across the internet so quickly ? they use audio and video compression algorithms . how does google maps figure out how to get from dallas , texas to orlando , florida so that you can get to disney world ? they use a route finding algorithm . how does pixar color a 3d model of a character based on the lighting in a virtual room ? they use a rendering algorithm . how does nasa choose how to arrange the solar panels on the international space station and when to rearrange them ? they use an optimization and a scheduling algorithm . those algorithms are more complex than our everyday algorithms like making a grilled cheese sandwich . but they boil down to the same thing , a set of steps to accomplish a task . if you know something about existing algorithms , you can save yourself some effort and make your programs faster by applying the right one . for example , let 's say that you 're writing a game and you want the user to be able to play against the computer . well , you could look at checkers games for inspiration . computer scientists have figured out how to write checkers programs that never lose by using the minimax search algorithm to search through the huge tree of possible moves . if your game is similar to checkers , then you might be able to use algorithms based on these techniques . if not , then knowing the limitations of those algorithms might lead you to redesign your game if it requires having a skilled computer player . it 's also important to know how to design new algorithms as well as how to analyze their correctness and efficiency . in the biological sciences , new algorithms are continually being designed with purposes like designing the molecular structures that are the core of disease fighting drugs . in physics , algorithms simulate climate and weather patterns . in other algorithms , search and analyze the vast data about stars in the universe that 's collected by automated space telescopes . across all the sciences , and even on websites like khan academy , efficient algorithms are needed to analyze huge data sets or to select intelligently from a vast number of possible decisions . in just about any area you might be interested , new algorithms will allow massive computational power to be harnessed to do things that people really need and care about . now , not all algorithms are created equal . so what makes a good algorithm ? the two most important criteria are that it solves a problem and that it does so efficiently . most of the time , we want an algorithm to give us an answer that we know is always correct . sometimes we can live with an algorithm that does n't give us the correct answer or the best answer because the only perfect algorithms that we know for those problems take a really , really long time . for example , let 's say we want a program that would determine the most efficient route for a truck that delivers packages , starting and ending the day at a depot . it would take weeks to run going through all the possibilities . but if we 're okay with a program that would determine a route that 's good but maybe not the best , then it could run in seconds . in some case , good is good enough . how do you measure the efficiency of an algorithm ? we could time how long it takes to run the code , but that would only tell us about that particular implementation in a certain programming language on a particular computer and just for the input it was given . instead , computer scientists use a technique called asymptotic analysis , which allows algorithms to be compared independently of a particular programming language or hardware so that we can conclusively say that yes , some algorithms are more efficient than others . now you can learn about algorithms and asymptotic analysis on khan academy thanks to the contribution of two dartmouth college professors . tom cormen is the first author of the most popular college algorithms textbook in the world , plus the author of algorithms unlocked . devin balkcom designed dartmouth 's intro cs course and researches robotics . he built the world 's first origami folding robot . tom and devin will teach you many of the algorithms that you would learn in apcs or cs 101 , like searching algorithms , sorting algorithms , recursive algorithms and my personal favorite , graph algorithms . there will be tons of interactive visualizations , quizzes and coding challenges to help you understand better along your learning journey .
|
how does google hangouts transmit live video across the internet so quickly ? they use audio and video compression algorithms . how does google maps figure out how to get from dallas , texas to orlando , florida so that you can get to disney world ?
|
what sort of algorithms does khan academy use ?
|
- [ voicover ] prejudice is made up of several different components . the first component that we have is a fundamental underlying thought overgeneralized belief , otherwise known as a cognition . we often refer to these as stereotypes . the second aspect to prejudice is that it carries with it an emotional component , like anger or a strong dislike , and we term that an affect , or affective component . and thirdly , predjudice consists of a propensity to carry out a behavior to act on the prejudice . and when somebody does that , it actually turns into discrimination . so as i 've earlier mentioned , cognition , a thought can otherwise be called a stereotype . and a tendency to lead to a behavior when a prejudicial way of thinking actually leads to a behaviorial change , that 's termed discrimination . so we can already see that we can break down prejudice into these three areas . well , when we think about prejudice , is there a kind of personality factor at play ? and there is a line of thinking to suggest that , yeah , there is a type of personality that could be more susceptible to prejudice , and that 's called the authoritarian personality . now , what i 'm gon na do here is to draw a big pair of military jackboots , lots of laces . because people with authoritarian personality , they 're kinda pretty militaristic in some ways . they kinda listen to their superiors , they 're pretty obedient to their superiors , i should say . but on the other hand , they do n't really have much sympathy or caring for people they deem to be inferior to themselves . they can actually be pretty oppressive to people that are under them . and they are pretty rigid thinkers , pretty inflexible with their viewpoints . some of you may be thinking , that does n't sound like a lot of fun . well , one of the things that we think about , and when we think about these people , we think that perhaps they actually had quite harsh upbringings . they probably underwent a lot of disciplining themselves when they were growing up . and people with this authoritarian personality , they actually use prejudice to help them cope with their world view , it 's actually protective of their ego . and prejudice avoids them having to confront the unacceptable aspects of themselves . they 're always focusing on other people , and how other people behave , and how other people act , and how much they hate or do n't like other people . now , this authoritarian personality , this is actually quite controversial , and i should mention that , and you have to know that not everybody agrees with this jackboot personality type . and one other thing you should think about , if it 's a personality type , it 's gon na be difficult to change . and that makes interventions to reduce prejudice by targeting authoritarian personalities more difficult . so what if it 's not to do with personality ? what if it 's to do with more so emotion rather than personality ? well , one of the ideas that has come up is the idea that something like frustration , so somebody getting very frustrated , that could actually , in some ways , lead to a prejudice . well , how exactly does that ? when somebody 's frustrated , one of the thoughts is that they become frustrated and that frustration very often turns into these aggressive impulses . right , so for example , you are working in a very low paid job . you get really frustrated and you start to get angry , and you start to get aggressive , and you start to get aggressive towards your employer for giving you such a crummy low paid job . well , one of the challenges is that if you start getting really aggressive to your employer , boom , you may lose your job . and you may not necessarily want that . so if you do n't become aggressive to your employer , if you start bottling up , this aggression 's gon na keep mounting up . so , what do some people do ? some people may take this aggression over here and may re-channel it somewhere else . so , instead of their employer , they may re-channel it towards minorities . this is much more acceptable in many ways , because when they do that , they 're not gon na lose their job . they can displace out their aggression towards other people , minorities , different racial groups . and what do we think they 're doing here ? they 're doing something we call scapegoating . so they are literally taking this frustration that 's turning into aggression , and instead of putting out their employer or other powerful figure , that it 's gon na be a disadvantage to them , they will re-channel it towards a different group of individuals . and historically , we have seen that throughout the world , throughout the us , throughout europe , in particular , times of economic hardship and disadvantage . and this theory is called the frustration aggression hypothesis . in line with the frustration aggression hypothesis , i want to tell you about another hypothesis . and this is called the hypothesis of relative deprivation . now , what the hypothesis of relative deprivation suggests is that people become very frustrated and you get upsurge in prejudice and discrimination when people feel deprived of something they feel entitled to . and there 's a discrepancy between what their expectations are , and what they actually get . so let 's look at this graph here , and let 's label the axis . label the horizontal axis as time , and label the vertical axis as , say standard of living . so if our expectation is that living standards increase gradually over time , and this is what we expect , and then what we actually get is this . so as you can see , living standards actually do n't increase with time , actually these tend to drop off , maybe because of some economic problem . we 're left with a difference . and it 's this difference that is the relative deprivation . and it 's the extent , and how quickly that relative deprivation comes about that can lead to collective unrest , an upsurge in prejudice and also discrimination , 'cause that 's the behavioral component that can occur after prejudice . so actually , the frustration aggression hypothesis , and the hypothesis of relative deprivation , these two things are linked .
|
in line with the frustration aggression hypothesis , i want to tell you about another hypothesis . and this is called the hypothesis of relative deprivation . now , what the hypothesis of relative deprivation suggests is that people become very frustrated and you get upsurge in prejudice and discrimination when people feel deprived of something they feel entitled to .
|
would conservatives ' negative reaction to obama 's immigration reform be considered a form of the hypothesis of relative deprivation because we 're all immigrants ?
|
- [ voicover ] prejudice is made up of several different components . the first component that we have is a fundamental underlying thought overgeneralized belief , otherwise known as a cognition . we often refer to these as stereotypes . the second aspect to prejudice is that it carries with it an emotional component , like anger or a strong dislike , and we term that an affect , or affective component . and thirdly , predjudice consists of a propensity to carry out a behavior to act on the prejudice . and when somebody does that , it actually turns into discrimination . so as i 've earlier mentioned , cognition , a thought can otherwise be called a stereotype . and a tendency to lead to a behavior when a prejudicial way of thinking actually leads to a behaviorial change , that 's termed discrimination . so we can already see that we can break down prejudice into these three areas . well , when we think about prejudice , is there a kind of personality factor at play ? and there is a line of thinking to suggest that , yeah , there is a type of personality that could be more susceptible to prejudice , and that 's called the authoritarian personality . now , what i 'm gon na do here is to draw a big pair of military jackboots , lots of laces . because people with authoritarian personality , they 're kinda pretty militaristic in some ways . they kinda listen to their superiors , they 're pretty obedient to their superiors , i should say . but on the other hand , they do n't really have much sympathy or caring for people they deem to be inferior to themselves . they can actually be pretty oppressive to people that are under them . and they are pretty rigid thinkers , pretty inflexible with their viewpoints . some of you may be thinking , that does n't sound like a lot of fun . well , one of the things that we think about , and when we think about these people , we think that perhaps they actually had quite harsh upbringings . they probably underwent a lot of disciplining themselves when they were growing up . and people with this authoritarian personality , they actually use prejudice to help them cope with their world view , it 's actually protective of their ego . and prejudice avoids them having to confront the unacceptable aspects of themselves . they 're always focusing on other people , and how other people behave , and how other people act , and how much they hate or do n't like other people . now , this authoritarian personality , this is actually quite controversial , and i should mention that , and you have to know that not everybody agrees with this jackboot personality type . and one other thing you should think about , if it 's a personality type , it 's gon na be difficult to change . and that makes interventions to reduce prejudice by targeting authoritarian personalities more difficult . so what if it 's not to do with personality ? what if it 's to do with more so emotion rather than personality ? well , one of the ideas that has come up is the idea that something like frustration , so somebody getting very frustrated , that could actually , in some ways , lead to a prejudice . well , how exactly does that ? when somebody 's frustrated , one of the thoughts is that they become frustrated and that frustration very often turns into these aggressive impulses . right , so for example , you are working in a very low paid job . you get really frustrated and you start to get angry , and you start to get aggressive , and you start to get aggressive towards your employer for giving you such a crummy low paid job . well , one of the challenges is that if you start getting really aggressive to your employer , boom , you may lose your job . and you may not necessarily want that . so if you do n't become aggressive to your employer , if you start bottling up , this aggression 's gon na keep mounting up . so , what do some people do ? some people may take this aggression over here and may re-channel it somewhere else . so , instead of their employer , they may re-channel it towards minorities . this is much more acceptable in many ways , because when they do that , they 're not gon na lose their job . they can displace out their aggression towards other people , minorities , different racial groups . and what do we think they 're doing here ? they 're doing something we call scapegoating . so they are literally taking this frustration that 's turning into aggression , and instead of putting out their employer or other powerful figure , that it 's gon na be a disadvantage to them , they will re-channel it towards a different group of individuals . and historically , we have seen that throughout the world , throughout the us , throughout europe , in particular , times of economic hardship and disadvantage . and this theory is called the frustration aggression hypothesis . in line with the frustration aggression hypothesis , i want to tell you about another hypothesis . and this is called the hypothesis of relative deprivation . now , what the hypothesis of relative deprivation suggests is that people become very frustrated and you get upsurge in prejudice and discrimination when people feel deprived of something they feel entitled to . and there 's a discrepancy between what their expectations are , and what they actually get . so let 's look at this graph here , and let 's label the axis . label the horizontal axis as time , and label the vertical axis as , say standard of living . so if our expectation is that living standards increase gradually over time , and this is what we expect , and then what we actually get is this . so as you can see , living standards actually do n't increase with time , actually these tend to drop off , maybe because of some economic problem . we 're left with a difference . and it 's this difference that is the relative deprivation . and it 's the extent , and how quickly that relative deprivation comes about that can lead to collective unrest , an upsurge in prejudice and also discrimination , 'cause that 's the behavioral component that can occur after prejudice . so actually , the frustration aggression hypothesis , and the hypothesis of relative deprivation , these two things are linked .
|
so as you can see , living standards actually do n't increase with time , actually these tend to drop off , maybe because of some economic problem . we 're left with a difference . and it 's this difference that is the relative deprivation .
|
i wonder what the difference is between the scapegoating mentioned in the video and the psychoanalytic idea of displacement ?
|
- [ voicover ] prejudice is made up of several different components . the first component that we have is a fundamental underlying thought overgeneralized belief , otherwise known as a cognition . we often refer to these as stereotypes . the second aspect to prejudice is that it carries with it an emotional component , like anger or a strong dislike , and we term that an affect , or affective component . and thirdly , predjudice consists of a propensity to carry out a behavior to act on the prejudice . and when somebody does that , it actually turns into discrimination . so as i 've earlier mentioned , cognition , a thought can otherwise be called a stereotype . and a tendency to lead to a behavior when a prejudicial way of thinking actually leads to a behaviorial change , that 's termed discrimination . so we can already see that we can break down prejudice into these three areas . well , when we think about prejudice , is there a kind of personality factor at play ? and there is a line of thinking to suggest that , yeah , there is a type of personality that could be more susceptible to prejudice , and that 's called the authoritarian personality . now , what i 'm gon na do here is to draw a big pair of military jackboots , lots of laces . because people with authoritarian personality , they 're kinda pretty militaristic in some ways . they kinda listen to their superiors , they 're pretty obedient to their superiors , i should say . but on the other hand , they do n't really have much sympathy or caring for people they deem to be inferior to themselves . they can actually be pretty oppressive to people that are under them . and they are pretty rigid thinkers , pretty inflexible with their viewpoints . some of you may be thinking , that does n't sound like a lot of fun . well , one of the things that we think about , and when we think about these people , we think that perhaps they actually had quite harsh upbringings . they probably underwent a lot of disciplining themselves when they were growing up . and people with this authoritarian personality , they actually use prejudice to help them cope with their world view , it 's actually protective of their ego . and prejudice avoids them having to confront the unacceptable aspects of themselves . they 're always focusing on other people , and how other people behave , and how other people act , and how much they hate or do n't like other people . now , this authoritarian personality , this is actually quite controversial , and i should mention that , and you have to know that not everybody agrees with this jackboot personality type . and one other thing you should think about , if it 's a personality type , it 's gon na be difficult to change . and that makes interventions to reduce prejudice by targeting authoritarian personalities more difficult . so what if it 's not to do with personality ? what if it 's to do with more so emotion rather than personality ? well , one of the ideas that has come up is the idea that something like frustration , so somebody getting very frustrated , that could actually , in some ways , lead to a prejudice . well , how exactly does that ? when somebody 's frustrated , one of the thoughts is that they become frustrated and that frustration very often turns into these aggressive impulses . right , so for example , you are working in a very low paid job . you get really frustrated and you start to get angry , and you start to get aggressive , and you start to get aggressive towards your employer for giving you such a crummy low paid job . well , one of the challenges is that if you start getting really aggressive to your employer , boom , you may lose your job . and you may not necessarily want that . so if you do n't become aggressive to your employer , if you start bottling up , this aggression 's gon na keep mounting up . so , what do some people do ? some people may take this aggression over here and may re-channel it somewhere else . so , instead of their employer , they may re-channel it towards minorities . this is much more acceptable in many ways , because when they do that , they 're not gon na lose their job . they can displace out their aggression towards other people , minorities , different racial groups . and what do we think they 're doing here ? they 're doing something we call scapegoating . so they are literally taking this frustration that 's turning into aggression , and instead of putting out their employer or other powerful figure , that it 's gon na be a disadvantage to them , they will re-channel it towards a different group of individuals . and historically , we have seen that throughout the world , throughout the us , throughout europe , in particular , times of economic hardship and disadvantage . and this theory is called the frustration aggression hypothesis . in line with the frustration aggression hypothesis , i want to tell you about another hypothesis . and this is called the hypothesis of relative deprivation . now , what the hypothesis of relative deprivation suggests is that people become very frustrated and you get upsurge in prejudice and discrimination when people feel deprived of something they feel entitled to . and there 's a discrepancy between what their expectations are , and what they actually get . so let 's look at this graph here , and let 's label the axis . label the horizontal axis as time , and label the vertical axis as , say standard of living . so if our expectation is that living standards increase gradually over time , and this is what we expect , and then what we actually get is this . so as you can see , living standards actually do n't increase with time , actually these tend to drop off , maybe because of some economic problem . we 're left with a difference . and it 's this difference that is the relative deprivation . and it 's the extent , and how quickly that relative deprivation comes about that can lead to collective unrest , an upsurge in prejudice and also discrimination , 'cause that 's the behavioral component that can occur after prejudice . so actually , the frustration aggression hypothesis , and the hypothesis of relative deprivation , these two things are linked .
|
in line with the frustration aggression hypothesis , i want to tell you about another hypothesis . and this is called the hypothesis of relative deprivation . now , what the hypothesis of relative deprivation suggests is that people become very frustrated and you get upsurge in prejudice and discrimination when people feel deprived of something they feel entitled to .
|
why is there upsurge of prejudice in the hypothesis of relative deprivation ?
|
stacy wants to find the derivative of f of x equals x squared plus one at the point x equals two . her table below shows the average rate of change of f over the intervals from x to two or from two to x , and these are closed intervals , for x-values that get increasingly closer to two . so they get -- so we 're talking about the average rate of change of f over these closed intervals for x-values that get increasingly closer to two . it looks like we 're going to be dealing with some type of a limit , or we 're trying to calculate some type of a limit , or approximate some type of a limit . let 's read this data here . these are the x values and she 's trying to find the average rate of change between each of these x-values and two , or the average rate of change of the function between when x is -- one of these x values and two , and then she has the average rate of change that she precalculated , so we do n't have to get a calculator out or anything like that , and just as a reminder , how did she calculate this 3.9 ? well , they tell us . she took f of 1.9 , what does the function equal when x is 1.9 ? from that , she subtracted what is the value of the function when f is equal to two , so that 's really our change in f , and she divided it by the x , which is 1.9 , minus two , so change in f over change in x . what is the average rate of change of our function over that interval ? she did it between 1.9 and two , she got 3.9 . then she gets closer to two , so now she 's doing it between 1.99 and two and it becomes 3.99 , it looks like it 's getting closer to four . she gets even closer to two and the average rate of change gets even closer to four , and then she goes on the other side of two , you could view it as this is approaching , this is -- this is approaching -- this is x approaching two from the left hand side , and this is x approaching two from the right hand side . when it 's 2.1 , the average rate of change is 4.1 . when it 's 2.01 , once again , we 're getting closer to two , we 're getting closer to two , the average rate of change is getting closer to four . the closer we get to two , the closer the average rate of change gets to four . what this data is really helping us approximate it 's really saying , okay , the average rate of change we know is f of x minus f of two , over x minus two , but what we 're really thinking about is , well what is the limit as x approaches two right over here ? that 's what this data is helping us to get at , and it looks like this limit is equal to four . they give us it in here , it says , `` look , the closer that x gets to two `` from either the left hand side or the right hand side , `` the closer that this expression right over here , `` which is this number , gets to four . '' you might recognize , this is one of the definitions of a derivative . this is one of the definitions of a derivative . this right over here would be f prime of two , the derivative at x equals two is equal to the limit as x approaches two of all of this business . there 's other ways to express a derivative as a limit but this is one of them . there you go , from the table , what does the derivative of f of x equals x squared plus one at x equals two appear to be ? well , the derivative at x equals two appears to be equal to four , and we 're done .
|
stacy wants to find the derivative of f of x equals x squared plus one at the point x equals two . her table below shows the average rate of change of f over the intervals from x to two or from two to x , and these are closed intervals , for x-values that get increasingly closer to two . so they get -- so we 're talking about the average rate of change of f over these closed intervals for x-values that get increasingly closer to two .
|
why do the order of those intervals change ?
|
stacy wants to find the derivative of f of x equals x squared plus one at the point x equals two . her table below shows the average rate of change of f over the intervals from x to two or from two to x , and these are closed intervals , for x-values that get increasingly closer to two . so they get -- so we 're talking about the average rate of change of f over these closed intervals for x-values that get increasingly closer to two . it looks like we 're going to be dealing with some type of a limit , or we 're trying to calculate some type of a limit , or approximate some type of a limit . let 's read this data here . these are the x values and she 's trying to find the average rate of change between each of these x-values and two , or the average rate of change of the function between when x is -- one of these x values and two , and then she has the average rate of change that she precalculated , so we do n't have to get a calculator out or anything like that , and just as a reminder , how did she calculate this 3.9 ? well , they tell us . she took f of 1.9 , what does the function equal when x is 1.9 ? from that , she subtracted what is the value of the function when f is equal to two , so that 's really our change in f , and she divided it by the x , which is 1.9 , minus two , so change in f over change in x . what is the average rate of change of our function over that interval ? she did it between 1.9 and two , she got 3.9 . then she gets closer to two , so now she 's doing it between 1.99 and two and it becomes 3.99 , it looks like it 's getting closer to four . she gets even closer to two and the average rate of change gets even closer to four , and then she goes on the other side of two , you could view it as this is approaching , this is -- this is approaching -- this is x approaching two from the left hand side , and this is x approaching two from the right hand side . when it 's 2.1 , the average rate of change is 4.1 . when it 's 2.01 , once again , we 're getting closer to two , we 're getting closer to two , the average rate of change is getting closer to four . the closer we get to two , the closer the average rate of change gets to four . what this data is really helping us approximate it 's really saying , okay , the average rate of change we know is f of x minus f of two , over x minus two , but what we 're really thinking about is , well what is the limit as x approaches two right over here ? that 's what this data is helping us to get at , and it looks like this limit is equal to four . they give us it in here , it says , `` look , the closer that x gets to two `` from either the left hand side or the right hand side , `` the closer that this expression right over here , `` which is this number , gets to four . '' you might recognize , this is one of the definitions of a derivative . this is one of the definitions of a derivative . this right over here would be f prime of two , the derivative at x equals two is equal to the limit as x approaches two of all of this business . there 's other ways to express a derivative as a limit but this is one of them . there you go , from the table , what does the derivative of f of x equals x squared plus one at x equals two appear to be ? well , the derivative at x equals two appears to be equal to four , and we 're done .
|
she gets even closer to two and the average rate of change gets even closer to four , and then she goes on the other side of two , you could view it as this is approaching , this is -- this is approaching -- this is x approaching two from the left hand side , and this is x approaching two from the right hand side . when it 's 2.1 , the average rate of change is 4.1 . when it 's 2.01 , once again , we 're getting closer to two , we 're getting closer to two , the average rate of change is getting closer to four .
|
and in the table , why do the interval switch side when going from 1.999 to 2.001 ?
|
stacy wants to find the derivative of f of x equals x squared plus one at the point x equals two . her table below shows the average rate of change of f over the intervals from x to two or from two to x , and these are closed intervals , for x-values that get increasingly closer to two . so they get -- so we 're talking about the average rate of change of f over these closed intervals for x-values that get increasingly closer to two . it looks like we 're going to be dealing with some type of a limit , or we 're trying to calculate some type of a limit , or approximate some type of a limit . let 's read this data here . these are the x values and she 's trying to find the average rate of change between each of these x-values and two , or the average rate of change of the function between when x is -- one of these x values and two , and then she has the average rate of change that she precalculated , so we do n't have to get a calculator out or anything like that , and just as a reminder , how did she calculate this 3.9 ? well , they tell us . she took f of 1.9 , what does the function equal when x is 1.9 ? from that , she subtracted what is the value of the function when f is equal to two , so that 's really our change in f , and she divided it by the x , which is 1.9 , minus two , so change in f over change in x . what is the average rate of change of our function over that interval ? she did it between 1.9 and two , she got 3.9 . then she gets closer to two , so now she 's doing it between 1.99 and two and it becomes 3.99 , it looks like it 's getting closer to four . she gets even closer to two and the average rate of change gets even closer to four , and then she goes on the other side of two , you could view it as this is approaching , this is -- this is approaching -- this is x approaching two from the left hand side , and this is x approaching two from the right hand side . when it 's 2.1 , the average rate of change is 4.1 . when it 's 2.01 , once again , we 're getting closer to two , we 're getting closer to two , the average rate of change is getting closer to four . the closer we get to two , the closer the average rate of change gets to four . what this data is really helping us approximate it 's really saying , okay , the average rate of change we know is f of x minus f of two , over x minus two , but what we 're really thinking about is , well what is the limit as x approaches two right over here ? that 's what this data is helping us to get at , and it looks like this limit is equal to four . they give us it in here , it says , `` look , the closer that x gets to two `` from either the left hand side or the right hand side , `` the closer that this expression right over here , `` which is this number , gets to four . '' you might recognize , this is one of the definitions of a derivative . this is one of the definitions of a derivative . this right over here would be f prime of two , the derivative at x equals two is equal to the limit as x approaches two of all of this business . there 's other ways to express a derivative as a limit but this is one of them . there you go , from the table , what does the derivative of f of x equals x squared plus one at x equals two appear to be ? well , the derivative at x equals two appears to be equal to four , and we 're done .
|
stacy wants to find the derivative of f of x equals x squared plus one at the point x equals two . her table below shows the average rate of change of f over the intervals from x to two or from two to x , and these are closed intervals , for x-values that get increasingly closer to two .
|
this might be a stupid question , but i have not been able to understand what the relation between d ( x ) and f ' ( x ) is , are they the same ?
|
stacy wants to find the derivative of f of x equals x squared plus one at the point x equals two . her table below shows the average rate of change of f over the intervals from x to two or from two to x , and these are closed intervals , for x-values that get increasingly closer to two . so they get -- so we 're talking about the average rate of change of f over these closed intervals for x-values that get increasingly closer to two . it looks like we 're going to be dealing with some type of a limit , or we 're trying to calculate some type of a limit , or approximate some type of a limit . let 's read this data here . these are the x values and she 's trying to find the average rate of change between each of these x-values and two , or the average rate of change of the function between when x is -- one of these x values and two , and then she has the average rate of change that she precalculated , so we do n't have to get a calculator out or anything like that , and just as a reminder , how did she calculate this 3.9 ? well , they tell us . she took f of 1.9 , what does the function equal when x is 1.9 ? from that , she subtracted what is the value of the function when f is equal to two , so that 's really our change in f , and she divided it by the x , which is 1.9 , minus two , so change in f over change in x . what is the average rate of change of our function over that interval ? she did it between 1.9 and two , she got 3.9 . then she gets closer to two , so now she 's doing it between 1.99 and two and it becomes 3.99 , it looks like it 's getting closer to four . she gets even closer to two and the average rate of change gets even closer to four , and then she goes on the other side of two , you could view it as this is approaching , this is -- this is approaching -- this is x approaching two from the left hand side , and this is x approaching two from the right hand side . when it 's 2.1 , the average rate of change is 4.1 . when it 's 2.01 , once again , we 're getting closer to two , we 're getting closer to two , the average rate of change is getting closer to four . the closer we get to two , the closer the average rate of change gets to four . what this data is really helping us approximate it 's really saying , okay , the average rate of change we know is f of x minus f of two , over x minus two , but what we 're really thinking about is , well what is the limit as x approaches two right over here ? that 's what this data is helping us to get at , and it looks like this limit is equal to four . they give us it in here , it says , `` look , the closer that x gets to two `` from either the left hand side or the right hand side , `` the closer that this expression right over here , `` which is this number , gets to four . '' you might recognize , this is one of the definitions of a derivative . this is one of the definitions of a derivative . this right over here would be f prime of two , the derivative at x equals two is equal to the limit as x approaches two of all of this business . there 's other ways to express a derivative as a limit but this is one of them . there you go , from the table , what does the derivative of f of x equals x squared plus one at x equals two appear to be ? well , the derivative at x equals two appears to be equal to four , and we 're done .
|
you might recognize , this is one of the definitions of a derivative . this is one of the definitions of a derivative . this right over here would be f prime of two , the derivative at x equals two is equal to the limit as x approaches two of all of this business .
|
how are definitions of derivative and limit same ?
|
let 's look at our gentleman in the middle . he is lying down and he is dreaming . that raises the question , do our dreams have a meaning ? so if he 's thinking about money , relationships , even weird and wonderful things like monsters chasing him down the road , what does that mean ? where are all these dreams coming from ? now , along came sigmund freud , a prominent neurologist and psychoanalyst , and what freud said in his theory of dreams is that dreams really represent our unconscious wishes , urges and feelings . that dreams are a way of understanding things that are typically hidden . now how do we understand that ? well , let 's take this iceberg , and let 's say that the bit of the iceberg above the water represents conscious wishes , urges , feelings and these are the things we actually know about and that we experience and that we consciously are aware of . but what you can see here underneath the water , there 's plenty more iceberg . and that actually represents , the unconscious . our unconscious wishes , urges and feelings . and it 's these unconscious elements that come out in our dreams . now freud actually went a little bit further and said we can break down dreams into two key components . the first one being , what is actually happening in our dreams . and this is actually referred to as the manifest content . so , if you dream of monsters chasing you , the manifest content is very much , monsters chasing you . the second part of freud breaking down dreams is what is the hidden meaning behind a dream ? and this is something that he termed , latent content . so the monsters chasing you , does that refer to you , being potentially chased out of your job or feeling insecure in your job because other people are getting a promotion ? what is the hidden meaning ? that 's how he broke down dreams . into the manifest and latent content . so , according to freud , dreams very much have a meaning on our lives . dreams and the interpretation of dreams , trying to understand what the dreams mean , can really help us to identify and resolve conflict . now , on the flip side of this , i 've got this picture of this brain here . and one the things that was also hypothesized to happen , is that in the brain , we get a lot of electrical impulses , neurons firing in this area called the brain stem . and these electrical impulses are sometimes interpreted by the `` thinking '' part of the brain , the frontal part of the brain . that may try to understand or make sense of all these kind of random impulses that keep firing and keep occurring during this period of rem sleep and rem stands for rapid eye movement sleep . it 's the time or part of sleep that our eyes are rapidly moving and we experience dreaming . so during rem sleep , we get these brain circuits , this brain activity in the brain stem . and then the cerebral cortex and frontal part of the brain , has to interpret that and make sense of that . so we can turn the brain stem activity as being activation , and the cerebral cortex trying to understand what 's happening as being , as trying to synthesize meaning , and this is very much a hypothesis , and if we put all of those together , we get the activation , synthesis hypothesis . which is what this is really called . and what i mentioned is that dreams are simply our brain is trying to find meaning in these random signals from the brain stem . so really , the dreams may not have any prominent meaning . so this is very much a way that we can split up these two key theories . on one side , freud feels that dreams indeed have a meaning and important to helping us to resolve hidden conflicts and understand unconcious feelings , desires , impulses , and that 's his theory of dreams . on the other hand , we have this activation synthesis hypothesis . that suggest that dreams are simply a part of our brain , the frontal part of the cerebral cortex , that more generalized thinking part of our brain , trying to make sense of these electrical impulses in the brain stem . so two , really contrasting ideas about the importance of dreams . there are some other theories , these are just two of them , but two of the more important ones that you should be aware of .
|
on one side , freud feels that dreams indeed have a meaning and important to helping us to resolve hidden conflicts and understand unconcious feelings , desires , impulses , and that 's his theory of dreams . on the other hand , we have this activation synthesis hypothesis . that suggest that dreams are simply a part of our brain , the frontal part of the cerebral cortex , that more generalized thinking part of our brain , trying to make sense of these electrical impulses in the brain stem .
|
in regards to the `` activation synthesis hypothesis '' dream theory , where do the electrical impulses come from , i would assume that since a person is asleep they are unable to perceive anything so what activity creates the electrical impulses ?
|
i 'm going to quickly sketch out the human heart . we 're also going to label some vessels coming off of it . so the big vessel , of course , is the aorta . this is the giant aortic arch . and the aortic arch has a couple of key branches that go , for example , up to the head and neck . it has other branches as well that go out to the arms . but these branches that are going up are the ones i 'm going to focus on . so out here on this right side , we have the right common carotid artery . and it 's called the common because , eventually , what 's going to happen is it 's going to bulge here , and then it 's going to split . and it 's going to split into the internal branch -- this is going inside -- and the external branch over here . so this would be called , for example , the right external carotid artery . and the same thing is happening on the other side , and we name it kind of the same way . we say , ok , there 's an internal branch and an external branch . this would be the internal , and this might be the external branch of the left common carotid artery . so i think you 're getting the idea now . these are named exactly the same way . and these are the ones we 're going to focus on . now , previously , we had talked about how , in these particular locations , in the internal side and then this bulgy side , we have what are called the carotid sinus . or sinuses , i suppose . but the carotid sinus is right there . and the sinus refers to any open area or open space . and there 's also an area over here in the aortic arch . and these two areas , they are the home for our baroreceptors . our baroreceptors are basically little nerves that are going to detect pressure . so they 're going to detect stretch , or pressure , that is in the vessels . and they 're going to give information back to the brain . and that 's going to help regulate our blood pressure . now , in this video , we 're actually going to focus on chemoreceptors . chemoreceptors are also important in giving us information , but they 're going to give us information about things like oxygen levels , carbon dioxide levels , ph of the blood , things like that . so these chemoreceptors -- and this gets confusing -- they 're located in a similar region , but not exactly the same region . i 'm actually going to shade in where our chemoreceptors might be , and then also you might get some over here . so these three areas are where chemoreceptors are . and they 're very , of course , closely related to where the baroreceptors are , but they 're actually in slightly different locations . and we call them the aortic body and the carotid body . and the reason we use the term `` body '' is that it 's a body of tissue . so that 's why that word gets used . and this is actually -- you can see now a slightly different location , and certainly a different job . so let me blow up some of these regions and show you , close up , what this might look like . so let me draw for you the carotid body on this side , and on the other side , we 'll do the aortic body . and i 'm basically just zooming in on it , so you can see up close what this might look like , so you can visualize it . so for the carotid body , you might have the external artery , the internal artery . and coming off of the external artery , you might have little branches , little branches serving this tissue that 's in the middle . and these branches , of course , are going to branch some more . and you 're going to get all the way down to the capillary level . and once you have little capillaries in here , there 's going to be a bunch of little cells . and these cells are , of course , going to get the nutrition from the capillary . and taken together , all these cells -- if you zoom out of this picture , this would be a little body of cells or body of tissue . and that 's why we call this the carotid body . and really , the same thing is going on on the aorta side . so on the aorta side , you 've got little branches coming off of the aorta , of course . and these branches are going to branch again , and again , and again , and again . and eventually , you 're going to get lots and lots of little capillaries . and these capillaries are going to serve all these little blue cells that i 'm drawing here , and these are the chemoreceptors that we 're talking about . so these blue cells together make up a body of tissue , and that 's where we get the term `` aortic body '' and `` carotid body . '' now , on the carotid side , one interesting fact is that this body of tissue gets a lot of blood flow , in fact , some of the highest blood flow in the entire human body . it 's about 2 liters per minute for 100 grams . and just to put that in perspective for the carotid body , imagine that you have a little 2-liter bottle of soda . i was thinking of something that would be about 2 liters , and soda came to mind . and you can imagine pouring this soda out over something that 's about 100 grams -- maybe a tomato . that 's about a 100-gram tomato . and if you could do this in one minute , if you could pour out this bottle in one minute , imagine how wet this tomato 's going to get , how much profusion , in a sense , this tomato is going to get . that is how much profusion your carotid body gets . so it really puts it in perspective how much blood flow 's going into that area . so let 's now zoom in a little bit further . let 's say i have a capillary . and inside my capillary , i 've got a little red blood cell here , floating around . and my red blood cell , of course , has some hemoglobin in it , which is a protein . and this protein has got some oxygen bound to it . i 'm going to draw little blue oxygen molecules . and of course , there 's some oxygen out here in the plasma itself as well . and if we 're in our carotid body or aortic body , you might have these special little blue cells that i 've been drawing , our peripheral chemoreceptor cells . and specifically they have a name . these things are called glomus cells . i had initially misstated it as a globus cell . but actually it 's an m -- glomus . and these oxygen molecules -- these are oxygen molecules over here -- are going to diffuse down into the tissue and get into our glomus cell . it 's going to look something like that . and if you have a lot of oxygen in the blood , of course , a lot of molecules are going to diffuse in . but if you do n't have too much in here , then not too much is going to make its way into the cell . and that 's actually the key point . because what our cell is going to be able to do is start to detect low oxygen levels . low oxygen levels in the glomus cell tells this cell that , actually , there are probably low levels in the blood . and when the levels are low , this cell is going to depolarize . its membrane is going to depolarize . and what it has on the other side are little vesicles that are full of neurotransmitter . and so when these vesicles detect that , hey , there 's a depolarization going on , these vesicles are going to dump their neurotransmitter out . and what you have waiting for them is this nice little neuron . so there 's a nice little neuron waiting patiently for a signal , and that signal is going to come in the form of a neurotransmitter . so this is how the communication works . there 's going to be a depolarization , the vessels release their neurotransmitter , and that is going to send an action potential down to our neuron . and if the oxygen levels fall really low , let 's say they get dangerously low , where the cell is very unhappy , then you 're going to get much more neurotransmitter getting dumped out , and you 're going to get many more action potentials . so this is how the glomus cell helps to detect oxygen . and in fact , it also detects carbon dioxide . because , remember , this cell is going to be making carbon dioxide . let 's say this is a little molecule of co2 , and that co2 is going to diffuse out and into the blood . well , let 's say that the blood has a lot of carbon dioxide already . let 's say that it 's loaded with carbon dioxide , lots and lots of it . in this situation , it 's going to be very difficult for carbon dioxide to make its way from the glomus cell all the way out into the plasma . and as a result , carbon dioxide starts building up . the tissue starts gathering more and more co2 , because it ca n't go anywhere . and this glomus cell is going to say , hey , wait a second . our co2 levels are starting to rise . there are high co2 levels . and again , that 's going to make the cell unhappy , and it 's going to send out more neurotransmitter , and it 's going to , of course , send out more action potentials . so two different reasons why you might get action potentials coming out of this glomus cell . and now i want to remind you that there 's this little formula . there 's this formula where carbon dioxide binds with water , and it forms h2co3 . and that 's going to break down into bicarbonate and a proton . so this is our formula . so if co2 levels are rising , like the example i just offered , then the proton level must be high as well . so a high proton concentration -- i 'm going to put it in brackets , to indicate concentration . or another way of saying that would be a low ph . so these are the things that are going to make our glomus cell send off more action potentials . so if you 're like me , you 're thinking , well , wait a second . this is really interesting . our cell is depolarizing . it can depolarize . it also has this neurotransmitter that i mentioned . our glomus cell , then , right here in blue , is basically sounding a little bit like it has properties of a nerve cell . this is a nerve cell . and the reason for that is that , if you actually take a look , these two cells have a common ancestor cell . and so in development , when the fetus is developing , there is a type of tissue called the neuroectoderm . and both of these cells , this nerve cell and this glomus cell , both are derived from this neuroectoderm . so it makes sense that they would have a lot of common features . so we know the glomus cell is not a neuron , but it 's going to be talking to neurons . in fact , you 're going to have many neurons working together in this area . and they 're going to join up , both in the aortic body and the carotid body . and these neurons , going back to the original picture , are going to meet up into a big nerve . and this nerve is going to be called the vagus nerve . the vagus nerve is going to be the one for our aortic body , sometimes also called cranial nerve number 10 . and up here with the carotid body , we have a nerve as well . this is another nerve . this one , we call the glossopharyngeal nerve . so these two nerves , the vagus nerve and the glossopharyngeal nerve -- this one , this glossopharyngeal nerve , by the way , is cranial nerve number 9 -- these two nerves are not part of the brain . they 're headed to the brain , right ? so these two nerves are fundamentally taking information from chemoreceptors that are outside of the brain . they 're not located in the brain , right ? they 're peripheral , and they 're taking information about chemicals and taking that information to the brain . that 's why we call them -- these blue areas , the carotid body and the aortic body -- we call them peripheral chemoreceptors .
|
and the aortic arch has a couple of key branches that go , for example , up to the head and neck . it has other branches as well that go out to the arms . but these branches that are going up are the ones i 'm going to focus on .
|
how does this go with lungs ?
|
i 'm going to quickly sketch out the human heart . we 're also going to label some vessels coming off of it . so the big vessel , of course , is the aorta . this is the giant aortic arch . and the aortic arch has a couple of key branches that go , for example , up to the head and neck . it has other branches as well that go out to the arms . but these branches that are going up are the ones i 'm going to focus on . so out here on this right side , we have the right common carotid artery . and it 's called the common because , eventually , what 's going to happen is it 's going to bulge here , and then it 's going to split . and it 's going to split into the internal branch -- this is going inside -- and the external branch over here . so this would be called , for example , the right external carotid artery . and the same thing is happening on the other side , and we name it kind of the same way . we say , ok , there 's an internal branch and an external branch . this would be the internal , and this might be the external branch of the left common carotid artery . so i think you 're getting the idea now . these are named exactly the same way . and these are the ones we 're going to focus on . now , previously , we had talked about how , in these particular locations , in the internal side and then this bulgy side , we have what are called the carotid sinus . or sinuses , i suppose . but the carotid sinus is right there . and the sinus refers to any open area or open space . and there 's also an area over here in the aortic arch . and these two areas , they are the home for our baroreceptors . our baroreceptors are basically little nerves that are going to detect pressure . so they 're going to detect stretch , or pressure , that is in the vessels . and they 're going to give information back to the brain . and that 's going to help regulate our blood pressure . now , in this video , we 're actually going to focus on chemoreceptors . chemoreceptors are also important in giving us information , but they 're going to give us information about things like oxygen levels , carbon dioxide levels , ph of the blood , things like that . so these chemoreceptors -- and this gets confusing -- they 're located in a similar region , but not exactly the same region . i 'm actually going to shade in where our chemoreceptors might be , and then also you might get some over here . so these three areas are where chemoreceptors are . and they 're very , of course , closely related to where the baroreceptors are , but they 're actually in slightly different locations . and we call them the aortic body and the carotid body . and the reason we use the term `` body '' is that it 's a body of tissue . so that 's why that word gets used . and this is actually -- you can see now a slightly different location , and certainly a different job . so let me blow up some of these regions and show you , close up , what this might look like . so let me draw for you the carotid body on this side , and on the other side , we 'll do the aortic body . and i 'm basically just zooming in on it , so you can see up close what this might look like , so you can visualize it . so for the carotid body , you might have the external artery , the internal artery . and coming off of the external artery , you might have little branches , little branches serving this tissue that 's in the middle . and these branches , of course , are going to branch some more . and you 're going to get all the way down to the capillary level . and once you have little capillaries in here , there 's going to be a bunch of little cells . and these cells are , of course , going to get the nutrition from the capillary . and taken together , all these cells -- if you zoom out of this picture , this would be a little body of cells or body of tissue . and that 's why we call this the carotid body . and really , the same thing is going on on the aorta side . so on the aorta side , you 've got little branches coming off of the aorta , of course . and these branches are going to branch again , and again , and again , and again . and eventually , you 're going to get lots and lots of little capillaries . and these capillaries are going to serve all these little blue cells that i 'm drawing here , and these are the chemoreceptors that we 're talking about . so these blue cells together make up a body of tissue , and that 's where we get the term `` aortic body '' and `` carotid body . '' now , on the carotid side , one interesting fact is that this body of tissue gets a lot of blood flow , in fact , some of the highest blood flow in the entire human body . it 's about 2 liters per minute for 100 grams . and just to put that in perspective for the carotid body , imagine that you have a little 2-liter bottle of soda . i was thinking of something that would be about 2 liters , and soda came to mind . and you can imagine pouring this soda out over something that 's about 100 grams -- maybe a tomato . that 's about a 100-gram tomato . and if you could do this in one minute , if you could pour out this bottle in one minute , imagine how wet this tomato 's going to get , how much profusion , in a sense , this tomato is going to get . that is how much profusion your carotid body gets . so it really puts it in perspective how much blood flow 's going into that area . so let 's now zoom in a little bit further . let 's say i have a capillary . and inside my capillary , i 've got a little red blood cell here , floating around . and my red blood cell , of course , has some hemoglobin in it , which is a protein . and this protein has got some oxygen bound to it . i 'm going to draw little blue oxygen molecules . and of course , there 's some oxygen out here in the plasma itself as well . and if we 're in our carotid body or aortic body , you might have these special little blue cells that i 've been drawing , our peripheral chemoreceptor cells . and specifically they have a name . these things are called glomus cells . i had initially misstated it as a globus cell . but actually it 's an m -- glomus . and these oxygen molecules -- these are oxygen molecules over here -- are going to diffuse down into the tissue and get into our glomus cell . it 's going to look something like that . and if you have a lot of oxygen in the blood , of course , a lot of molecules are going to diffuse in . but if you do n't have too much in here , then not too much is going to make its way into the cell . and that 's actually the key point . because what our cell is going to be able to do is start to detect low oxygen levels . low oxygen levels in the glomus cell tells this cell that , actually , there are probably low levels in the blood . and when the levels are low , this cell is going to depolarize . its membrane is going to depolarize . and what it has on the other side are little vesicles that are full of neurotransmitter . and so when these vesicles detect that , hey , there 's a depolarization going on , these vesicles are going to dump their neurotransmitter out . and what you have waiting for them is this nice little neuron . so there 's a nice little neuron waiting patiently for a signal , and that signal is going to come in the form of a neurotransmitter . so this is how the communication works . there 's going to be a depolarization , the vessels release their neurotransmitter , and that is going to send an action potential down to our neuron . and if the oxygen levels fall really low , let 's say they get dangerously low , where the cell is very unhappy , then you 're going to get much more neurotransmitter getting dumped out , and you 're going to get many more action potentials . so this is how the glomus cell helps to detect oxygen . and in fact , it also detects carbon dioxide . because , remember , this cell is going to be making carbon dioxide . let 's say this is a little molecule of co2 , and that co2 is going to diffuse out and into the blood . well , let 's say that the blood has a lot of carbon dioxide already . let 's say that it 's loaded with carbon dioxide , lots and lots of it . in this situation , it 's going to be very difficult for carbon dioxide to make its way from the glomus cell all the way out into the plasma . and as a result , carbon dioxide starts building up . the tissue starts gathering more and more co2 , because it ca n't go anywhere . and this glomus cell is going to say , hey , wait a second . our co2 levels are starting to rise . there are high co2 levels . and again , that 's going to make the cell unhappy , and it 's going to send out more neurotransmitter , and it 's going to , of course , send out more action potentials . so two different reasons why you might get action potentials coming out of this glomus cell . and now i want to remind you that there 's this little formula . there 's this formula where carbon dioxide binds with water , and it forms h2co3 . and that 's going to break down into bicarbonate and a proton . so this is our formula . so if co2 levels are rising , like the example i just offered , then the proton level must be high as well . so a high proton concentration -- i 'm going to put it in brackets , to indicate concentration . or another way of saying that would be a low ph . so these are the things that are going to make our glomus cell send off more action potentials . so if you 're like me , you 're thinking , well , wait a second . this is really interesting . our cell is depolarizing . it can depolarize . it also has this neurotransmitter that i mentioned . our glomus cell , then , right here in blue , is basically sounding a little bit like it has properties of a nerve cell . this is a nerve cell . and the reason for that is that , if you actually take a look , these two cells have a common ancestor cell . and so in development , when the fetus is developing , there is a type of tissue called the neuroectoderm . and both of these cells , this nerve cell and this glomus cell , both are derived from this neuroectoderm . so it makes sense that they would have a lot of common features . so we know the glomus cell is not a neuron , but it 's going to be talking to neurons . in fact , you 're going to have many neurons working together in this area . and they 're going to join up , both in the aortic body and the carotid body . and these neurons , going back to the original picture , are going to meet up into a big nerve . and this nerve is going to be called the vagus nerve . the vagus nerve is going to be the one for our aortic body , sometimes also called cranial nerve number 10 . and up here with the carotid body , we have a nerve as well . this is another nerve . this one , we call the glossopharyngeal nerve . so these two nerves , the vagus nerve and the glossopharyngeal nerve -- this one , this glossopharyngeal nerve , by the way , is cranial nerve number 9 -- these two nerves are not part of the brain . they 're headed to the brain , right ? so these two nerves are fundamentally taking information from chemoreceptors that are outside of the brain . they 're not located in the brain , right ? they 're peripheral , and they 're taking information about chemicals and taking that information to the brain . that 's why we call them -- these blue areas , the carotid body and the aortic body -- we call them peripheral chemoreceptors .
|
and really , the same thing is going on on the aorta side . so on the aorta side , you 've got little branches coming off of the aorta , of course . and these branches are going to branch again , and again , and again , and again .
|
why does it appear that the aorta is coming from the right ventricle ?
|
i 'm going to quickly sketch out the human heart . we 're also going to label some vessels coming off of it . so the big vessel , of course , is the aorta . this is the giant aortic arch . and the aortic arch has a couple of key branches that go , for example , up to the head and neck . it has other branches as well that go out to the arms . but these branches that are going up are the ones i 'm going to focus on . so out here on this right side , we have the right common carotid artery . and it 's called the common because , eventually , what 's going to happen is it 's going to bulge here , and then it 's going to split . and it 's going to split into the internal branch -- this is going inside -- and the external branch over here . so this would be called , for example , the right external carotid artery . and the same thing is happening on the other side , and we name it kind of the same way . we say , ok , there 's an internal branch and an external branch . this would be the internal , and this might be the external branch of the left common carotid artery . so i think you 're getting the idea now . these are named exactly the same way . and these are the ones we 're going to focus on . now , previously , we had talked about how , in these particular locations , in the internal side and then this bulgy side , we have what are called the carotid sinus . or sinuses , i suppose . but the carotid sinus is right there . and the sinus refers to any open area or open space . and there 's also an area over here in the aortic arch . and these two areas , they are the home for our baroreceptors . our baroreceptors are basically little nerves that are going to detect pressure . so they 're going to detect stretch , or pressure , that is in the vessels . and they 're going to give information back to the brain . and that 's going to help regulate our blood pressure . now , in this video , we 're actually going to focus on chemoreceptors . chemoreceptors are also important in giving us information , but they 're going to give us information about things like oxygen levels , carbon dioxide levels , ph of the blood , things like that . so these chemoreceptors -- and this gets confusing -- they 're located in a similar region , but not exactly the same region . i 'm actually going to shade in where our chemoreceptors might be , and then also you might get some over here . so these three areas are where chemoreceptors are . and they 're very , of course , closely related to where the baroreceptors are , but they 're actually in slightly different locations . and we call them the aortic body and the carotid body . and the reason we use the term `` body '' is that it 's a body of tissue . so that 's why that word gets used . and this is actually -- you can see now a slightly different location , and certainly a different job . so let me blow up some of these regions and show you , close up , what this might look like . so let me draw for you the carotid body on this side , and on the other side , we 'll do the aortic body . and i 'm basically just zooming in on it , so you can see up close what this might look like , so you can visualize it . so for the carotid body , you might have the external artery , the internal artery . and coming off of the external artery , you might have little branches , little branches serving this tissue that 's in the middle . and these branches , of course , are going to branch some more . and you 're going to get all the way down to the capillary level . and once you have little capillaries in here , there 's going to be a bunch of little cells . and these cells are , of course , going to get the nutrition from the capillary . and taken together , all these cells -- if you zoom out of this picture , this would be a little body of cells or body of tissue . and that 's why we call this the carotid body . and really , the same thing is going on on the aorta side . so on the aorta side , you 've got little branches coming off of the aorta , of course . and these branches are going to branch again , and again , and again , and again . and eventually , you 're going to get lots and lots of little capillaries . and these capillaries are going to serve all these little blue cells that i 'm drawing here , and these are the chemoreceptors that we 're talking about . so these blue cells together make up a body of tissue , and that 's where we get the term `` aortic body '' and `` carotid body . '' now , on the carotid side , one interesting fact is that this body of tissue gets a lot of blood flow , in fact , some of the highest blood flow in the entire human body . it 's about 2 liters per minute for 100 grams . and just to put that in perspective for the carotid body , imagine that you have a little 2-liter bottle of soda . i was thinking of something that would be about 2 liters , and soda came to mind . and you can imagine pouring this soda out over something that 's about 100 grams -- maybe a tomato . that 's about a 100-gram tomato . and if you could do this in one minute , if you could pour out this bottle in one minute , imagine how wet this tomato 's going to get , how much profusion , in a sense , this tomato is going to get . that is how much profusion your carotid body gets . so it really puts it in perspective how much blood flow 's going into that area . so let 's now zoom in a little bit further . let 's say i have a capillary . and inside my capillary , i 've got a little red blood cell here , floating around . and my red blood cell , of course , has some hemoglobin in it , which is a protein . and this protein has got some oxygen bound to it . i 'm going to draw little blue oxygen molecules . and of course , there 's some oxygen out here in the plasma itself as well . and if we 're in our carotid body or aortic body , you might have these special little blue cells that i 've been drawing , our peripheral chemoreceptor cells . and specifically they have a name . these things are called glomus cells . i had initially misstated it as a globus cell . but actually it 's an m -- glomus . and these oxygen molecules -- these are oxygen molecules over here -- are going to diffuse down into the tissue and get into our glomus cell . it 's going to look something like that . and if you have a lot of oxygen in the blood , of course , a lot of molecules are going to diffuse in . but if you do n't have too much in here , then not too much is going to make its way into the cell . and that 's actually the key point . because what our cell is going to be able to do is start to detect low oxygen levels . low oxygen levels in the glomus cell tells this cell that , actually , there are probably low levels in the blood . and when the levels are low , this cell is going to depolarize . its membrane is going to depolarize . and what it has on the other side are little vesicles that are full of neurotransmitter . and so when these vesicles detect that , hey , there 's a depolarization going on , these vesicles are going to dump their neurotransmitter out . and what you have waiting for them is this nice little neuron . so there 's a nice little neuron waiting patiently for a signal , and that signal is going to come in the form of a neurotransmitter . so this is how the communication works . there 's going to be a depolarization , the vessels release their neurotransmitter , and that is going to send an action potential down to our neuron . and if the oxygen levels fall really low , let 's say they get dangerously low , where the cell is very unhappy , then you 're going to get much more neurotransmitter getting dumped out , and you 're going to get many more action potentials . so this is how the glomus cell helps to detect oxygen . and in fact , it also detects carbon dioxide . because , remember , this cell is going to be making carbon dioxide . let 's say this is a little molecule of co2 , and that co2 is going to diffuse out and into the blood . well , let 's say that the blood has a lot of carbon dioxide already . let 's say that it 's loaded with carbon dioxide , lots and lots of it . in this situation , it 's going to be very difficult for carbon dioxide to make its way from the glomus cell all the way out into the plasma . and as a result , carbon dioxide starts building up . the tissue starts gathering more and more co2 , because it ca n't go anywhere . and this glomus cell is going to say , hey , wait a second . our co2 levels are starting to rise . there are high co2 levels . and again , that 's going to make the cell unhappy , and it 's going to send out more neurotransmitter , and it 's going to , of course , send out more action potentials . so two different reasons why you might get action potentials coming out of this glomus cell . and now i want to remind you that there 's this little formula . there 's this formula where carbon dioxide binds with water , and it forms h2co3 . and that 's going to break down into bicarbonate and a proton . so this is our formula . so if co2 levels are rising , like the example i just offered , then the proton level must be high as well . so a high proton concentration -- i 'm going to put it in brackets , to indicate concentration . or another way of saying that would be a low ph . so these are the things that are going to make our glomus cell send off more action potentials . so if you 're like me , you 're thinking , well , wait a second . this is really interesting . our cell is depolarizing . it can depolarize . it also has this neurotransmitter that i mentioned . our glomus cell , then , right here in blue , is basically sounding a little bit like it has properties of a nerve cell . this is a nerve cell . and the reason for that is that , if you actually take a look , these two cells have a common ancestor cell . and so in development , when the fetus is developing , there is a type of tissue called the neuroectoderm . and both of these cells , this nerve cell and this glomus cell , both are derived from this neuroectoderm . so it makes sense that they would have a lot of common features . so we know the glomus cell is not a neuron , but it 's going to be talking to neurons . in fact , you 're going to have many neurons working together in this area . and they 're going to join up , both in the aortic body and the carotid body . and these neurons , going back to the original picture , are going to meet up into a big nerve . and this nerve is going to be called the vagus nerve . the vagus nerve is going to be the one for our aortic body , sometimes also called cranial nerve number 10 . and up here with the carotid body , we have a nerve as well . this is another nerve . this one , we call the glossopharyngeal nerve . so these two nerves , the vagus nerve and the glossopharyngeal nerve -- this one , this glossopharyngeal nerve , by the way , is cranial nerve number 9 -- these two nerves are not part of the brain . they 're headed to the brain , right ? so these two nerves are fundamentally taking information from chemoreceptors that are outside of the brain . they 're not located in the brain , right ? they 're peripheral , and they 're taking information about chemicals and taking that information to the brain . that 's why we call them -- these blue areas , the carotid body and the aortic body -- we call them peripheral chemoreceptors .
|
and these oxygen molecules -- these are oxygen molecules over here -- are going to diffuse down into the tissue and get into our glomus cell . it 's going to look something like that . and if you have a lot of oxygen in the blood , of course , a lot of molecules are going to diffuse in .
|
why do we draw hearts like that when they dont look like that ?
|
i 'm going to quickly sketch out the human heart . we 're also going to label some vessels coming off of it . so the big vessel , of course , is the aorta . this is the giant aortic arch . and the aortic arch has a couple of key branches that go , for example , up to the head and neck . it has other branches as well that go out to the arms . but these branches that are going up are the ones i 'm going to focus on . so out here on this right side , we have the right common carotid artery . and it 's called the common because , eventually , what 's going to happen is it 's going to bulge here , and then it 's going to split . and it 's going to split into the internal branch -- this is going inside -- and the external branch over here . so this would be called , for example , the right external carotid artery . and the same thing is happening on the other side , and we name it kind of the same way . we say , ok , there 's an internal branch and an external branch . this would be the internal , and this might be the external branch of the left common carotid artery . so i think you 're getting the idea now . these are named exactly the same way . and these are the ones we 're going to focus on . now , previously , we had talked about how , in these particular locations , in the internal side and then this bulgy side , we have what are called the carotid sinus . or sinuses , i suppose . but the carotid sinus is right there . and the sinus refers to any open area or open space . and there 's also an area over here in the aortic arch . and these two areas , they are the home for our baroreceptors . our baroreceptors are basically little nerves that are going to detect pressure . so they 're going to detect stretch , or pressure , that is in the vessels . and they 're going to give information back to the brain . and that 's going to help regulate our blood pressure . now , in this video , we 're actually going to focus on chemoreceptors . chemoreceptors are also important in giving us information , but they 're going to give us information about things like oxygen levels , carbon dioxide levels , ph of the blood , things like that . so these chemoreceptors -- and this gets confusing -- they 're located in a similar region , but not exactly the same region . i 'm actually going to shade in where our chemoreceptors might be , and then also you might get some over here . so these three areas are where chemoreceptors are . and they 're very , of course , closely related to where the baroreceptors are , but they 're actually in slightly different locations . and we call them the aortic body and the carotid body . and the reason we use the term `` body '' is that it 's a body of tissue . so that 's why that word gets used . and this is actually -- you can see now a slightly different location , and certainly a different job . so let me blow up some of these regions and show you , close up , what this might look like . so let me draw for you the carotid body on this side , and on the other side , we 'll do the aortic body . and i 'm basically just zooming in on it , so you can see up close what this might look like , so you can visualize it . so for the carotid body , you might have the external artery , the internal artery . and coming off of the external artery , you might have little branches , little branches serving this tissue that 's in the middle . and these branches , of course , are going to branch some more . and you 're going to get all the way down to the capillary level . and once you have little capillaries in here , there 's going to be a bunch of little cells . and these cells are , of course , going to get the nutrition from the capillary . and taken together , all these cells -- if you zoom out of this picture , this would be a little body of cells or body of tissue . and that 's why we call this the carotid body . and really , the same thing is going on on the aorta side . so on the aorta side , you 've got little branches coming off of the aorta , of course . and these branches are going to branch again , and again , and again , and again . and eventually , you 're going to get lots and lots of little capillaries . and these capillaries are going to serve all these little blue cells that i 'm drawing here , and these are the chemoreceptors that we 're talking about . so these blue cells together make up a body of tissue , and that 's where we get the term `` aortic body '' and `` carotid body . '' now , on the carotid side , one interesting fact is that this body of tissue gets a lot of blood flow , in fact , some of the highest blood flow in the entire human body . it 's about 2 liters per minute for 100 grams . and just to put that in perspective for the carotid body , imagine that you have a little 2-liter bottle of soda . i was thinking of something that would be about 2 liters , and soda came to mind . and you can imagine pouring this soda out over something that 's about 100 grams -- maybe a tomato . that 's about a 100-gram tomato . and if you could do this in one minute , if you could pour out this bottle in one minute , imagine how wet this tomato 's going to get , how much profusion , in a sense , this tomato is going to get . that is how much profusion your carotid body gets . so it really puts it in perspective how much blood flow 's going into that area . so let 's now zoom in a little bit further . let 's say i have a capillary . and inside my capillary , i 've got a little red blood cell here , floating around . and my red blood cell , of course , has some hemoglobin in it , which is a protein . and this protein has got some oxygen bound to it . i 'm going to draw little blue oxygen molecules . and of course , there 's some oxygen out here in the plasma itself as well . and if we 're in our carotid body or aortic body , you might have these special little blue cells that i 've been drawing , our peripheral chemoreceptor cells . and specifically they have a name . these things are called glomus cells . i had initially misstated it as a globus cell . but actually it 's an m -- glomus . and these oxygen molecules -- these are oxygen molecules over here -- are going to diffuse down into the tissue and get into our glomus cell . it 's going to look something like that . and if you have a lot of oxygen in the blood , of course , a lot of molecules are going to diffuse in . but if you do n't have too much in here , then not too much is going to make its way into the cell . and that 's actually the key point . because what our cell is going to be able to do is start to detect low oxygen levels . low oxygen levels in the glomus cell tells this cell that , actually , there are probably low levels in the blood . and when the levels are low , this cell is going to depolarize . its membrane is going to depolarize . and what it has on the other side are little vesicles that are full of neurotransmitter . and so when these vesicles detect that , hey , there 's a depolarization going on , these vesicles are going to dump their neurotransmitter out . and what you have waiting for them is this nice little neuron . so there 's a nice little neuron waiting patiently for a signal , and that signal is going to come in the form of a neurotransmitter . so this is how the communication works . there 's going to be a depolarization , the vessels release their neurotransmitter , and that is going to send an action potential down to our neuron . and if the oxygen levels fall really low , let 's say they get dangerously low , where the cell is very unhappy , then you 're going to get much more neurotransmitter getting dumped out , and you 're going to get many more action potentials . so this is how the glomus cell helps to detect oxygen . and in fact , it also detects carbon dioxide . because , remember , this cell is going to be making carbon dioxide . let 's say this is a little molecule of co2 , and that co2 is going to diffuse out and into the blood . well , let 's say that the blood has a lot of carbon dioxide already . let 's say that it 's loaded with carbon dioxide , lots and lots of it . in this situation , it 's going to be very difficult for carbon dioxide to make its way from the glomus cell all the way out into the plasma . and as a result , carbon dioxide starts building up . the tissue starts gathering more and more co2 , because it ca n't go anywhere . and this glomus cell is going to say , hey , wait a second . our co2 levels are starting to rise . there are high co2 levels . and again , that 's going to make the cell unhappy , and it 's going to send out more neurotransmitter , and it 's going to , of course , send out more action potentials . so two different reasons why you might get action potentials coming out of this glomus cell . and now i want to remind you that there 's this little formula . there 's this formula where carbon dioxide binds with water , and it forms h2co3 . and that 's going to break down into bicarbonate and a proton . so this is our formula . so if co2 levels are rising , like the example i just offered , then the proton level must be high as well . so a high proton concentration -- i 'm going to put it in brackets , to indicate concentration . or another way of saying that would be a low ph . so these are the things that are going to make our glomus cell send off more action potentials . so if you 're like me , you 're thinking , well , wait a second . this is really interesting . our cell is depolarizing . it can depolarize . it also has this neurotransmitter that i mentioned . our glomus cell , then , right here in blue , is basically sounding a little bit like it has properties of a nerve cell . this is a nerve cell . and the reason for that is that , if you actually take a look , these two cells have a common ancestor cell . and so in development , when the fetus is developing , there is a type of tissue called the neuroectoderm . and both of these cells , this nerve cell and this glomus cell , both are derived from this neuroectoderm . so it makes sense that they would have a lot of common features . so we know the glomus cell is not a neuron , but it 's going to be talking to neurons . in fact , you 're going to have many neurons working together in this area . and they 're going to join up , both in the aortic body and the carotid body . and these neurons , going back to the original picture , are going to meet up into a big nerve . and this nerve is going to be called the vagus nerve . the vagus nerve is going to be the one for our aortic body , sometimes also called cranial nerve number 10 . and up here with the carotid body , we have a nerve as well . this is another nerve . this one , we call the glossopharyngeal nerve . so these two nerves , the vagus nerve and the glossopharyngeal nerve -- this one , this glossopharyngeal nerve , by the way , is cranial nerve number 9 -- these two nerves are not part of the brain . they 're headed to the brain , right ? so these two nerves are fundamentally taking information from chemoreceptors that are outside of the brain . they 're not located in the brain , right ? they 're peripheral , and they 're taking information about chemicals and taking that information to the brain . that 's why we call them -- these blue areas , the carotid body and the aortic body -- we call them peripheral chemoreceptors .
|
this is really interesting . our cell is depolarizing . it can depolarize .
|
at 05 , the causes of the depolarization of the glomus cell are low pressure of oxygen , high pressure of carbon dioxide , and low ph , but is n't chemoreceptor detect chemical/concentration ?
|
i 'm going to quickly sketch out the human heart . we 're also going to label some vessels coming off of it . so the big vessel , of course , is the aorta . this is the giant aortic arch . and the aortic arch has a couple of key branches that go , for example , up to the head and neck . it has other branches as well that go out to the arms . but these branches that are going up are the ones i 'm going to focus on . so out here on this right side , we have the right common carotid artery . and it 's called the common because , eventually , what 's going to happen is it 's going to bulge here , and then it 's going to split . and it 's going to split into the internal branch -- this is going inside -- and the external branch over here . so this would be called , for example , the right external carotid artery . and the same thing is happening on the other side , and we name it kind of the same way . we say , ok , there 's an internal branch and an external branch . this would be the internal , and this might be the external branch of the left common carotid artery . so i think you 're getting the idea now . these are named exactly the same way . and these are the ones we 're going to focus on . now , previously , we had talked about how , in these particular locations , in the internal side and then this bulgy side , we have what are called the carotid sinus . or sinuses , i suppose . but the carotid sinus is right there . and the sinus refers to any open area or open space . and there 's also an area over here in the aortic arch . and these two areas , they are the home for our baroreceptors . our baroreceptors are basically little nerves that are going to detect pressure . so they 're going to detect stretch , or pressure , that is in the vessels . and they 're going to give information back to the brain . and that 's going to help regulate our blood pressure . now , in this video , we 're actually going to focus on chemoreceptors . chemoreceptors are also important in giving us information , but they 're going to give us information about things like oxygen levels , carbon dioxide levels , ph of the blood , things like that . so these chemoreceptors -- and this gets confusing -- they 're located in a similar region , but not exactly the same region . i 'm actually going to shade in where our chemoreceptors might be , and then also you might get some over here . so these three areas are where chemoreceptors are . and they 're very , of course , closely related to where the baroreceptors are , but they 're actually in slightly different locations . and we call them the aortic body and the carotid body . and the reason we use the term `` body '' is that it 's a body of tissue . so that 's why that word gets used . and this is actually -- you can see now a slightly different location , and certainly a different job . so let me blow up some of these regions and show you , close up , what this might look like . so let me draw for you the carotid body on this side , and on the other side , we 'll do the aortic body . and i 'm basically just zooming in on it , so you can see up close what this might look like , so you can visualize it . so for the carotid body , you might have the external artery , the internal artery . and coming off of the external artery , you might have little branches , little branches serving this tissue that 's in the middle . and these branches , of course , are going to branch some more . and you 're going to get all the way down to the capillary level . and once you have little capillaries in here , there 's going to be a bunch of little cells . and these cells are , of course , going to get the nutrition from the capillary . and taken together , all these cells -- if you zoom out of this picture , this would be a little body of cells or body of tissue . and that 's why we call this the carotid body . and really , the same thing is going on on the aorta side . so on the aorta side , you 've got little branches coming off of the aorta , of course . and these branches are going to branch again , and again , and again , and again . and eventually , you 're going to get lots and lots of little capillaries . and these capillaries are going to serve all these little blue cells that i 'm drawing here , and these are the chemoreceptors that we 're talking about . so these blue cells together make up a body of tissue , and that 's where we get the term `` aortic body '' and `` carotid body . '' now , on the carotid side , one interesting fact is that this body of tissue gets a lot of blood flow , in fact , some of the highest blood flow in the entire human body . it 's about 2 liters per minute for 100 grams . and just to put that in perspective for the carotid body , imagine that you have a little 2-liter bottle of soda . i was thinking of something that would be about 2 liters , and soda came to mind . and you can imagine pouring this soda out over something that 's about 100 grams -- maybe a tomato . that 's about a 100-gram tomato . and if you could do this in one minute , if you could pour out this bottle in one minute , imagine how wet this tomato 's going to get , how much profusion , in a sense , this tomato is going to get . that is how much profusion your carotid body gets . so it really puts it in perspective how much blood flow 's going into that area . so let 's now zoom in a little bit further . let 's say i have a capillary . and inside my capillary , i 've got a little red blood cell here , floating around . and my red blood cell , of course , has some hemoglobin in it , which is a protein . and this protein has got some oxygen bound to it . i 'm going to draw little blue oxygen molecules . and of course , there 's some oxygen out here in the plasma itself as well . and if we 're in our carotid body or aortic body , you might have these special little blue cells that i 've been drawing , our peripheral chemoreceptor cells . and specifically they have a name . these things are called glomus cells . i had initially misstated it as a globus cell . but actually it 's an m -- glomus . and these oxygen molecules -- these are oxygen molecules over here -- are going to diffuse down into the tissue and get into our glomus cell . it 's going to look something like that . and if you have a lot of oxygen in the blood , of course , a lot of molecules are going to diffuse in . but if you do n't have too much in here , then not too much is going to make its way into the cell . and that 's actually the key point . because what our cell is going to be able to do is start to detect low oxygen levels . low oxygen levels in the glomus cell tells this cell that , actually , there are probably low levels in the blood . and when the levels are low , this cell is going to depolarize . its membrane is going to depolarize . and what it has on the other side are little vesicles that are full of neurotransmitter . and so when these vesicles detect that , hey , there 's a depolarization going on , these vesicles are going to dump their neurotransmitter out . and what you have waiting for them is this nice little neuron . so there 's a nice little neuron waiting patiently for a signal , and that signal is going to come in the form of a neurotransmitter . so this is how the communication works . there 's going to be a depolarization , the vessels release their neurotransmitter , and that is going to send an action potential down to our neuron . and if the oxygen levels fall really low , let 's say they get dangerously low , where the cell is very unhappy , then you 're going to get much more neurotransmitter getting dumped out , and you 're going to get many more action potentials . so this is how the glomus cell helps to detect oxygen . and in fact , it also detects carbon dioxide . because , remember , this cell is going to be making carbon dioxide . let 's say this is a little molecule of co2 , and that co2 is going to diffuse out and into the blood . well , let 's say that the blood has a lot of carbon dioxide already . let 's say that it 's loaded with carbon dioxide , lots and lots of it . in this situation , it 's going to be very difficult for carbon dioxide to make its way from the glomus cell all the way out into the plasma . and as a result , carbon dioxide starts building up . the tissue starts gathering more and more co2 , because it ca n't go anywhere . and this glomus cell is going to say , hey , wait a second . our co2 levels are starting to rise . there are high co2 levels . and again , that 's going to make the cell unhappy , and it 's going to send out more neurotransmitter , and it 's going to , of course , send out more action potentials . so two different reasons why you might get action potentials coming out of this glomus cell . and now i want to remind you that there 's this little formula . there 's this formula where carbon dioxide binds with water , and it forms h2co3 . and that 's going to break down into bicarbonate and a proton . so this is our formula . so if co2 levels are rising , like the example i just offered , then the proton level must be high as well . so a high proton concentration -- i 'm going to put it in brackets , to indicate concentration . or another way of saying that would be a low ph . so these are the things that are going to make our glomus cell send off more action potentials . so if you 're like me , you 're thinking , well , wait a second . this is really interesting . our cell is depolarizing . it can depolarize . it also has this neurotransmitter that i mentioned . our glomus cell , then , right here in blue , is basically sounding a little bit like it has properties of a nerve cell . this is a nerve cell . and the reason for that is that , if you actually take a look , these two cells have a common ancestor cell . and so in development , when the fetus is developing , there is a type of tissue called the neuroectoderm . and both of these cells , this nerve cell and this glomus cell , both are derived from this neuroectoderm . so it makes sense that they would have a lot of common features . so we know the glomus cell is not a neuron , but it 's going to be talking to neurons . in fact , you 're going to have many neurons working together in this area . and they 're going to join up , both in the aortic body and the carotid body . and these neurons , going back to the original picture , are going to meet up into a big nerve . and this nerve is going to be called the vagus nerve . the vagus nerve is going to be the one for our aortic body , sometimes also called cranial nerve number 10 . and up here with the carotid body , we have a nerve as well . this is another nerve . this one , we call the glossopharyngeal nerve . so these two nerves , the vagus nerve and the glossopharyngeal nerve -- this one , this glossopharyngeal nerve , by the way , is cranial nerve number 9 -- these two nerves are not part of the brain . they 're headed to the brain , right ? so these two nerves are fundamentally taking information from chemoreceptors that are outside of the brain . they 're not located in the brain , right ? they 're peripheral , and they 're taking information about chemicals and taking that information to the brain . that 's why we call them -- these blue areas , the carotid body and the aortic body -- we call them peripheral chemoreceptors .
|
and if the oxygen levels fall really low , let 's say they get dangerously low , where the cell is very unhappy , then you 're going to get much more neurotransmitter getting dumped out , and you 're going to get many more action potentials . so this is how the glomus cell helps to detect oxygen . and in fact , it also detects carbon dioxide . because , remember , this cell is going to be making carbon dioxide .
|
why is it pressure of oxygen / carbon dioxides are the causes ?
|
i 'm going to quickly sketch out the human heart . we 're also going to label some vessels coming off of it . so the big vessel , of course , is the aorta . this is the giant aortic arch . and the aortic arch has a couple of key branches that go , for example , up to the head and neck . it has other branches as well that go out to the arms . but these branches that are going up are the ones i 'm going to focus on . so out here on this right side , we have the right common carotid artery . and it 's called the common because , eventually , what 's going to happen is it 's going to bulge here , and then it 's going to split . and it 's going to split into the internal branch -- this is going inside -- and the external branch over here . so this would be called , for example , the right external carotid artery . and the same thing is happening on the other side , and we name it kind of the same way . we say , ok , there 's an internal branch and an external branch . this would be the internal , and this might be the external branch of the left common carotid artery . so i think you 're getting the idea now . these are named exactly the same way . and these are the ones we 're going to focus on . now , previously , we had talked about how , in these particular locations , in the internal side and then this bulgy side , we have what are called the carotid sinus . or sinuses , i suppose . but the carotid sinus is right there . and the sinus refers to any open area or open space . and there 's also an area over here in the aortic arch . and these two areas , they are the home for our baroreceptors . our baroreceptors are basically little nerves that are going to detect pressure . so they 're going to detect stretch , or pressure , that is in the vessels . and they 're going to give information back to the brain . and that 's going to help regulate our blood pressure . now , in this video , we 're actually going to focus on chemoreceptors . chemoreceptors are also important in giving us information , but they 're going to give us information about things like oxygen levels , carbon dioxide levels , ph of the blood , things like that . so these chemoreceptors -- and this gets confusing -- they 're located in a similar region , but not exactly the same region . i 'm actually going to shade in where our chemoreceptors might be , and then also you might get some over here . so these three areas are where chemoreceptors are . and they 're very , of course , closely related to where the baroreceptors are , but they 're actually in slightly different locations . and we call them the aortic body and the carotid body . and the reason we use the term `` body '' is that it 's a body of tissue . so that 's why that word gets used . and this is actually -- you can see now a slightly different location , and certainly a different job . so let me blow up some of these regions and show you , close up , what this might look like . so let me draw for you the carotid body on this side , and on the other side , we 'll do the aortic body . and i 'm basically just zooming in on it , so you can see up close what this might look like , so you can visualize it . so for the carotid body , you might have the external artery , the internal artery . and coming off of the external artery , you might have little branches , little branches serving this tissue that 's in the middle . and these branches , of course , are going to branch some more . and you 're going to get all the way down to the capillary level . and once you have little capillaries in here , there 's going to be a bunch of little cells . and these cells are , of course , going to get the nutrition from the capillary . and taken together , all these cells -- if you zoom out of this picture , this would be a little body of cells or body of tissue . and that 's why we call this the carotid body . and really , the same thing is going on on the aorta side . so on the aorta side , you 've got little branches coming off of the aorta , of course . and these branches are going to branch again , and again , and again , and again . and eventually , you 're going to get lots and lots of little capillaries . and these capillaries are going to serve all these little blue cells that i 'm drawing here , and these are the chemoreceptors that we 're talking about . so these blue cells together make up a body of tissue , and that 's where we get the term `` aortic body '' and `` carotid body . '' now , on the carotid side , one interesting fact is that this body of tissue gets a lot of blood flow , in fact , some of the highest blood flow in the entire human body . it 's about 2 liters per minute for 100 grams . and just to put that in perspective for the carotid body , imagine that you have a little 2-liter bottle of soda . i was thinking of something that would be about 2 liters , and soda came to mind . and you can imagine pouring this soda out over something that 's about 100 grams -- maybe a tomato . that 's about a 100-gram tomato . and if you could do this in one minute , if you could pour out this bottle in one minute , imagine how wet this tomato 's going to get , how much profusion , in a sense , this tomato is going to get . that is how much profusion your carotid body gets . so it really puts it in perspective how much blood flow 's going into that area . so let 's now zoom in a little bit further . let 's say i have a capillary . and inside my capillary , i 've got a little red blood cell here , floating around . and my red blood cell , of course , has some hemoglobin in it , which is a protein . and this protein has got some oxygen bound to it . i 'm going to draw little blue oxygen molecules . and of course , there 's some oxygen out here in the plasma itself as well . and if we 're in our carotid body or aortic body , you might have these special little blue cells that i 've been drawing , our peripheral chemoreceptor cells . and specifically they have a name . these things are called glomus cells . i had initially misstated it as a globus cell . but actually it 's an m -- glomus . and these oxygen molecules -- these are oxygen molecules over here -- are going to diffuse down into the tissue and get into our glomus cell . it 's going to look something like that . and if you have a lot of oxygen in the blood , of course , a lot of molecules are going to diffuse in . but if you do n't have too much in here , then not too much is going to make its way into the cell . and that 's actually the key point . because what our cell is going to be able to do is start to detect low oxygen levels . low oxygen levels in the glomus cell tells this cell that , actually , there are probably low levels in the blood . and when the levels are low , this cell is going to depolarize . its membrane is going to depolarize . and what it has on the other side are little vesicles that are full of neurotransmitter . and so when these vesicles detect that , hey , there 's a depolarization going on , these vesicles are going to dump their neurotransmitter out . and what you have waiting for them is this nice little neuron . so there 's a nice little neuron waiting patiently for a signal , and that signal is going to come in the form of a neurotransmitter . so this is how the communication works . there 's going to be a depolarization , the vessels release their neurotransmitter , and that is going to send an action potential down to our neuron . and if the oxygen levels fall really low , let 's say they get dangerously low , where the cell is very unhappy , then you 're going to get much more neurotransmitter getting dumped out , and you 're going to get many more action potentials . so this is how the glomus cell helps to detect oxygen . and in fact , it also detects carbon dioxide . because , remember , this cell is going to be making carbon dioxide . let 's say this is a little molecule of co2 , and that co2 is going to diffuse out and into the blood . well , let 's say that the blood has a lot of carbon dioxide already . let 's say that it 's loaded with carbon dioxide , lots and lots of it . in this situation , it 's going to be very difficult for carbon dioxide to make its way from the glomus cell all the way out into the plasma . and as a result , carbon dioxide starts building up . the tissue starts gathering more and more co2 , because it ca n't go anywhere . and this glomus cell is going to say , hey , wait a second . our co2 levels are starting to rise . there are high co2 levels . and again , that 's going to make the cell unhappy , and it 's going to send out more neurotransmitter , and it 's going to , of course , send out more action potentials . so two different reasons why you might get action potentials coming out of this glomus cell . and now i want to remind you that there 's this little formula . there 's this formula where carbon dioxide binds with water , and it forms h2co3 . and that 's going to break down into bicarbonate and a proton . so this is our formula . so if co2 levels are rising , like the example i just offered , then the proton level must be high as well . so a high proton concentration -- i 'm going to put it in brackets , to indicate concentration . or another way of saying that would be a low ph . so these are the things that are going to make our glomus cell send off more action potentials . so if you 're like me , you 're thinking , well , wait a second . this is really interesting . our cell is depolarizing . it can depolarize . it also has this neurotransmitter that i mentioned . our glomus cell , then , right here in blue , is basically sounding a little bit like it has properties of a nerve cell . this is a nerve cell . and the reason for that is that , if you actually take a look , these two cells have a common ancestor cell . and so in development , when the fetus is developing , there is a type of tissue called the neuroectoderm . and both of these cells , this nerve cell and this glomus cell , both are derived from this neuroectoderm . so it makes sense that they would have a lot of common features . so we know the glomus cell is not a neuron , but it 's going to be talking to neurons . in fact , you 're going to have many neurons working together in this area . and they 're going to join up , both in the aortic body and the carotid body . and these neurons , going back to the original picture , are going to meet up into a big nerve . and this nerve is going to be called the vagus nerve . the vagus nerve is going to be the one for our aortic body , sometimes also called cranial nerve number 10 . and up here with the carotid body , we have a nerve as well . this is another nerve . this one , we call the glossopharyngeal nerve . so these two nerves , the vagus nerve and the glossopharyngeal nerve -- this one , this glossopharyngeal nerve , by the way , is cranial nerve number 9 -- these two nerves are not part of the brain . they 're headed to the brain , right ? so these two nerves are fundamentally taking information from chemoreceptors that are outside of the brain . they 're not located in the brain , right ? they 're peripheral , and they 're taking information about chemicals and taking that information to the brain . that 's why we call them -- these blue areas , the carotid body and the aortic body -- we call them peripheral chemoreceptors .
|
this is really interesting . our cell is depolarizing . it can depolarize .
|
so , what would be the name of the actual neurotransmitter that is released as a response to the glomus cell depolarizing ?
|
i 'm going to quickly sketch out the human heart . we 're also going to label some vessels coming off of it . so the big vessel , of course , is the aorta . this is the giant aortic arch . and the aortic arch has a couple of key branches that go , for example , up to the head and neck . it has other branches as well that go out to the arms . but these branches that are going up are the ones i 'm going to focus on . so out here on this right side , we have the right common carotid artery . and it 's called the common because , eventually , what 's going to happen is it 's going to bulge here , and then it 's going to split . and it 's going to split into the internal branch -- this is going inside -- and the external branch over here . so this would be called , for example , the right external carotid artery . and the same thing is happening on the other side , and we name it kind of the same way . we say , ok , there 's an internal branch and an external branch . this would be the internal , and this might be the external branch of the left common carotid artery . so i think you 're getting the idea now . these are named exactly the same way . and these are the ones we 're going to focus on . now , previously , we had talked about how , in these particular locations , in the internal side and then this bulgy side , we have what are called the carotid sinus . or sinuses , i suppose . but the carotid sinus is right there . and the sinus refers to any open area or open space . and there 's also an area over here in the aortic arch . and these two areas , they are the home for our baroreceptors . our baroreceptors are basically little nerves that are going to detect pressure . so they 're going to detect stretch , or pressure , that is in the vessels . and they 're going to give information back to the brain . and that 's going to help regulate our blood pressure . now , in this video , we 're actually going to focus on chemoreceptors . chemoreceptors are also important in giving us information , but they 're going to give us information about things like oxygen levels , carbon dioxide levels , ph of the blood , things like that . so these chemoreceptors -- and this gets confusing -- they 're located in a similar region , but not exactly the same region . i 'm actually going to shade in where our chemoreceptors might be , and then also you might get some over here . so these three areas are where chemoreceptors are . and they 're very , of course , closely related to where the baroreceptors are , but they 're actually in slightly different locations . and we call them the aortic body and the carotid body . and the reason we use the term `` body '' is that it 's a body of tissue . so that 's why that word gets used . and this is actually -- you can see now a slightly different location , and certainly a different job . so let me blow up some of these regions and show you , close up , what this might look like . so let me draw for you the carotid body on this side , and on the other side , we 'll do the aortic body . and i 'm basically just zooming in on it , so you can see up close what this might look like , so you can visualize it . so for the carotid body , you might have the external artery , the internal artery . and coming off of the external artery , you might have little branches , little branches serving this tissue that 's in the middle . and these branches , of course , are going to branch some more . and you 're going to get all the way down to the capillary level . and once you have little capillaries in here , there 's going to be a bunch of little cells . and these cells are , of course , going to get the nutrition from the capillary . and taken together , all these cells -- if you zoom out of this picture , this would be a little body of cells or body of tissue . and that 's why we call this the carotid body . and really , the same thing is going on on the aorta side . so on the aorta side , you 've got little branches coming off of the aorta , of course . and these branches are going to branch again , and again , and again , and again . and eventually , you 're going to get lots and lots of little capillaries . and these capillaries are going to serve all these little blue cells that i 'm drawing here , and these are the chemoreceptors that we 're talking about . so these blue cells together make up a body of tissue , and that 's where we get the term `` aortic body '' and `` carotid body . '' now , on the carotid side , one interesting fact is that this body of tissue gets a lot of blood flow , in fact , some of the highest blood flow in the entire human body . it 's about 2 liters per minute for 100 grams . and just to put that in perspective for the carotid body , imagine that you have a little 2-liter bottle of soda . i was thinking of something that would be about 2 liters , and soda came to mind . and you can imagine pouring this soda out over something that 's about 100 grams -- maybe a tomato . that 's about a 100-gram tomato . and if you could do this in one minute , if you could pour out this bottle in one minute , imagine how wet this tomato 's going to get , how much profusion , in a sense , this tomato is going to get . that is how much profusion your carotid body gets . so it really puts it in perspective how much blood flow 's going into that area . so let 's now zoom in a little bit further . let 's say i have a capillary . and inside my capillary , i 've got a little red blood cell here , floating around . and my red blood cell , of course , has some hemoglobin in it , which is a protein . and this protein has got some oxygen bound to it . i 'm going to draw little blue oxygen molecules . and of course , there 's some oxygen out here in the plasma itself as well . and if we 're in our carotid body or aortic body , you might have these special little blue cells that i 've been drawing , our peripheral chemoreceptor cells . and specifically they have a name . these things are called glomus cells . i had initially misstated it as a globus cell . but actually it 's an m -- glomus . and these oxygen molecules -- these are oxygen molecules over here -- are going to diffuse down into the tissue and get into our glomus cell . it 's going to look something like that . and if you have a lot of oxygen in the blood , of course , a lot of molecules are going to diffuse in . but if you do n't have too much in here , then not too much is going to make its way into the cell . and that 's actually the key point . because what our cell is going to be able to do is start to detect low oxygen levels . low oxygen levels in the glomus cell tells this cell that , actually , there are probably low levels in the blood . and when the levels are low , this cell is going to depolarize . its membrane is going to depolarize . and what it has on the other side are little vesicles that are full of neurotransmitter . and so when these vesicles detect that , hey , there 's a depolarization going on , these vesicles are going to dump their neurotransmitter out . and what you have waiting for them is this nice little neuron . so there 's a nice little neuron waiting patiently for a signal , and that signal is going to come in the form of a neurotransmitter . so this is how the communication works . there 's going to be a depolarization , the vessels release their neurotransmitter , and that is going to send an action potential down to our neuron . and if the oxygen levels fall really low , let 's say they get dangerously low , where the cell is very unhappy , then you 're going to get much more neurotransmitter getting dumped out , and you 're going to get many more action potentials . so this is how the glomus cell helps to detect oxygen . and in fact , it also detects carbon dioxide . because , remember , this cell is going to be making carbon dioxide . let 's say this is a little molecule of co2 , and that co2 is going to diffuse out and into the blood . well , let 's say that the blood has a lot of carbon dioxide already . let 's say that it 's loaded with carbon dioxide , lots and lots of it . in this situation , it 's going to be very difficult for carbon dioxide to make its way from the glomus cell all the way out into the plasma . and as a result , carbon dioxide starts building up . the tissue starts gathering more and more co2 , because it ca n't go anywhere . and this glomus cell is going to say , hey , wait a second . our co2 levels are starting to rise . there are high co2 levels . and again , that 's going to make the cell unhappy , and it 's going to send out more neurotransmitter , and it 's going to , of course , send out more action potentials . so two different reasons why you might get action potentials coming out of this glomus cell . and now i want to remind you that there 's this little formula . there 's this formula where carbon dioxide binds with water , and it forms h2co3 . and that 's going to break down into bicarbonate and a proton . so this is our formula . so if co2 levels are rising , like the example i just offered , then the proton level must be high as well . so a high proton concentration -- i 'm going to put it in brackets , to indicate concentration . or another way of saying that would be a low ph . so these are the things that are going to make our glomus cell send off more action potentials . so if you 're like me , you 're thinking , well , wait a second . this is really interesting . our cell is depolarizing . it can depolarize . it also has this neurotransmitter that i mentioned . our glomus cell , then , right here in blue , is basically sounding a little bit like it has properties of a nerve cell . this is a nerve cell . and the reason for that is that , if you actually take a look , these two cells have a common ancestor cell . and so in development , when the fetus is developing , there is a type of tissue called the neuroectoderm . and both of these cells , this nerve cell and this glomus cell , both are derived from this neuroectoderm . so it makes sense that they would have a lot of common features . so we know the glomus cell is not a neuron , but it 's going to be talking to neurons . in fact , you 're going to have many neurons working together in this area . and they 're going to join up , both in the aortic body and the carotid body . and these neurons , going back to the original picture , are going to meet up into a big nerve . and this nerve is going to be called the vagus nerve . the vagus nerve is going to be the one for our aortic body , sometimes also called cranial nerve number 10 . and up here with the carotid body , we have a nerve as well . this is another nerve . this one , we call the glossopharyngeal nerve . so these two nerves , the vagus nerve and the glossopharyngeal nerve -- this one , this glossopharyngeal nerve , by the way , is cranial nerve number 9 -- these two nerves are not part of the brain . they 're headed to the brain , right ? so these two nerves are fundamentally taking information from chemoreceptors that are outside of the brain . they 're not located in the brain , right ? they 're peripheral , and they 're taking information about chemicals and taking that information to the brain . that 's why we call them -- these blue areas , the carotid body and the aortic body -- we call them peripheral chemoreceptors .
|
and now i want to remind you that there 's this little formula . there 's this formula where carbon dioxide binds with water , and it forms h2co3 . and that 's going to break down into bicarbonate and a proton .
|
in h2co3 what does the 3 stand for ?
|
i 'm going to quickly sketch out the human heart . we 're also going to label some vessels coming off of it . so the big vessel , of course , is the aorta . this is the giant aortic arch . and the aortic arch has a couple of key branches that go , for example , up to the head and neck . it has other branches as well that go out to the arms . but these branches that are going up are the ones i 'm going to focus on . so out here on this right side , we have the right common carotid artery . and it 's called the common because , eventually , what 's going to happen is it 's going to bulge here , and then it 's going to split . and it 's going to split into the internal branch -- this is going inside -- and the external branch over here . so this would be called , for example , the right external carotid artery . and the same thing is happening on the other side , and we name it kind of the same way . we say , ok , there 's an internal branch and an external branch . this would be the internal , and this might be the external branch of the left common carotid artery . so i think you 're getting the idea now . these are named exactly the same way . and these are the ones we 're going to focus on . now , previously , we had talked about how , in these particular locations , in the internal side and then this bulgy side , we have what are called the carotid sinus . or sinuses , i suppose . but the carotid sinus is right there . and the sinus refers to any open area or open space . and there 's also an area over here in the aortic arch . and these two areas , they are the home for our baroreceptors . our baroreceptors are basically little nerves that are going to detect pressure . so they 're going to detect stretch , or pressure , that is in the vessels . and they 're going to give information back to the brain . and that 's going to help regulate our blood pressure . now , in this video , we 're actually going to focus on chemoreceptors . chemoreceptors are also important in giving us information , but they 're going to give us information about things like oxygen levels , carbon dioxide levels , ph of the blood , things like that . so these chemoreceptors -- and this gets confusing -- they 're located in a similar region , but not exactly the same region . i 'm actually going to shade in where our chemoreceptors might be , and then also you might get some over here . so these three areas are where chemoreceptors are . and they 're very , of course , closely related to where the baroreceptors are , but they 're actually in slightly different locations . and we call them the aortic body and the carotid body . and the reason we use the term `` body '' is that it 's a body of tissue . so that 's why that word gets used . and this is actually -- you can see now a slightly different location , and certainly a different job . so let me blow up some of these regions and show you , close up , what this might look like . so let me draw for you the carotid body on this side , and on the other side , we 'll do the aortic body . and i 'm basically just zooming in on it , so you can see up close what this might look like , so you can visualize it . so for the carotid body , you might have the external artery , the internal artery . and coming off of the external artery , you might have little branches , little branches serving this tissue that 's in the middle . and these branches , of course , are going to branch some more . and you 're going to get all the way down to the capillary level . and once you have little capillaries in here , there 's going to be a bunch of little cells . and these cells are , of course , going to get the nutrition from the capillary . and taken together , all these cells -- if you zoom out of this picture , this would be a little body of cells or body of tissue . and that 's why we call this the carotid body . and really , the same thing is going on on the aorta side . so on the aorta side , you 've got little branches coming off of the aorta , of course . and these branches are going to branch again , and again , and again , and again . and eventually , you 're going to get lots and lots of little capillaries . and these capillaries are going to serve all these little blue cells that i 'm drawing here , and these are the chemoreceptors that we 're talking about . so these blue cells together make up a body of tissue , and that 's where we get the term `` aortic body '' and `` carotid body . '' now , on the carotid side , one interesting fact is that this body of tissue gets a lot of blood flow , in fact , some of the highest blood flow in the entire human body . it 's about 2 liters per minute for 100 grams . and just to put that in perspective for the carotid body , imagine that you have a little 2-liter bottle of soda . i was thinking of something that would be about 2 liters , and soda came to mind . and you can imagine pouring this soda out over something that 's about 100 grams -- maybe a tomato . that 's about a 100-gram tomato . and if you could do this in one minute , if you could pour out this bottle in one minute , imagine how wet this tomato 's going to get , how much profusion , in a sense , this tomato is going to get . that is how much profusion your carotid body gets . so it really puts it in perspective how much blood flow 's going into that area . so let 's now zoom in a little bit further . let 's say i have a capillary . and inside my capillary , i 've got a little red blood cell here , floating around . and my red blood cell , of course , has some hemoglobin in it , which is a protein . and this protein has got some oxygen bound to it . i 'm going to draw little blue oxygen molecules . and of course , there 's some oxygen out here in the plasma itself as well . and if we 're in our carotid body or aortic body , you might have these special little blue cells that i 've been drawing , our peripheral chemoreceptor cells . and specifically they have a name . these things are called glomus cells . i had initially misstated it as a globus cell . but actually it 's an m -- glomus . and these oxygen molecules -- these are oxygen molecules over here -- are going to diffuse down into the tissue and get into our glomus cell . it 's going to look something like that . and if you have a lot of oxygen in the blood , of course , a lot of molecules are going to diffuse in . but if you do n't have too much in here , then not too much is going to make its way into the cell . and that 's actually the key point . because what our cell is going to be able to do is start to detect low oxygen levels . low oxygen levels in the glomus cell tells this cell that , actually , there are probably low levels in the blood . and when the levels are low , this cell is going to depolarize . its membrane is going to depolarize . and what it has on the other side are little vesicles that are full of neurotransmitter . and so when these vesicles detect that , hey , there 's a depolarization going on , these vesicles are going to dump their neurotransmitter out . and what you have waiting for them is this nice little neuron . so there 's a nice little neuron waiting patiently for a signal , and that signal is going to come in the form of a neurotransmitter . so this is how the communication works . there 's going to be a depolarization , the vessels release their neurotransmitter , and that is going to send an action potential down to our neuron . and if the oxygen levels fall really low , let 's say they get dangerously low , where the cell is very unhappy , then you 're going to get much more neurotransmitter getting dumped out , and you 're going to get many more action potentials . so this is how the glomus cell helps to detect oxygen . and in fact , it also detects carbon dioxide . because , remember , this cell is going to be making carbon dioxide . let 's say this is a little molecule of co2 , and that co2 is going to diffuse out and into the blood . well , let 's say that the blood has a lot of carbon dioxide already . let 's say that it 's loaded with carbon dioxide , lots and lots of it . in this situation , it 's going to be very difficult for carbon dioxide to make its way from the glomus cell all the way out into the plasma . and as a result , carbon dioxide starts building up . the tissue starts gathering more and more co2 , because it ca n't go anywhere . and this glomus cell is going to say , hey , wait a second . our co2 levels are starting to rise . there are high co2 levels . and again , that 's going to make the cell unhappy , and it 's going to send out more neurotransmitter , and it 's going to , of course , send out more action potentials . so two different reasons why you might get action potentials coming out of this glomus cell . and now i want to remind you that there 's this little formula . there 's this formula where carbon dioxide binds with water , and it forms h2co3 . and that 's going to break down into bicarbonate and a proton . so this is our formula . so if co2 levels are rising , like the example i just offered , then the proton level must be high as well . so a high proton concentration -- i 'm going to put it in brackets , to indicate concentration . or another way of saying that would be a low ph . so these are the things that are going to make our glomus cell send off more action potentials . so if you 're like me , you 're thinking , well , wait a second . this is really interesting . our cell is depolarizing . it can depolarize . it also has this neurotransmitter that i mentioned . our glomus cell , then , right here in blue , is basically sounding a little bit like it has properties of a nerve cell . this is a nerve cell . and the reason for that is that , if you actually take a look , these two cells have a common ancestor cell . and so in development , when the fetus is developing , there is a type of tissue called the neuroectoderm . and both of these cells , this nerve cell and this glomus cell , both are derived from this neuroectoderm . so it makes sense that they would have a lot of common features . so we know the glomus cell is not a neuron , but it 's going to be talking to neurons . in fact , you 're going to have many neurons working together in this area . and they 're going to join up , both in the aortic body and the carotid body . and these neurons , going back to the original picture , are going to meet up into a big nerve . and this nerve is going to be called the vagus nerve . the vagus nerve is going to be the one for our aortic body , sometimes also called cranial nerve number 10 . and up here with the carotid body , we have a nerve as well . this is another nerve . this one , we call the glossopharyngeal nerve . so these two nerves , the vagus nerve and the glossopharyngeal nerve -- this one , this glossopharyngeal nerve , by the way , is cranial nerve number 9 -- these two nerves are not part of the brain . they 're headed to the brain , right ? so these two nerves are fundamentally taking information from chemoreceptors that are outside of the brain . they 're not located in the brain , right ? they 're peripheral , and they 're taking information about chemicals and taking that information to the brain . that 's why we call them -- these blue areas , the carotid body and the aortic body -- we call them peripheral chemoreceptors .
|
so this is how the glomus cell helps to detect oxygen . and in fact , it also detects carbon dioxide . because , remember , this cell is going to be making carbon dioxide .
|
if someone had carbon monoxide poisoning , would this affect the interpretation of the chemoreceptors ?
|
i 'm going to quickly sketch out the human heart . we 're also going to label some vessels coming off of it . so the big vessel , of course , is the aorta . this is the giant aortic arch . and the aortic arch has a couple of key branches that go , for example , up to the head and neck . it has other branches as well that go out to the arms . but these branches that are going up are the ones i 'm going to focus on . so out here on this right side , we have the right common carotid artery . and it 's called the common because , eventually , what 's going to happen is it 's going to bulge here , and then it 's going to split . and it 's going to split into the internal branch -- this is going inside -- and the external branch over here . so this would be called , for example , the right external carotid artery . and the same thing is happening on the other side , and we name it kind of the same way . we say , ok , there 's an internal branch and an external branch . this would be the internal , and this might be the external branch of the left common carotid artery . so i think you 're getting the idea now . these are named exactly the same way . and these are the ones we 're going to focus on . now , previously , we had talked about how , in these particular locations , in the internal side and then this bulgy side , we have what are called the carotid sinus . or sinuses , i suppose . but the carotid sinus is right there . and the sinus refers to any open area or open space . and there 's also an area over here in the aortic arch . and these two areas , they are the home for our baroreceptors . our baroreceptors are basically little nerves that are going to detect pressure . so they 're going to detect stretch , or pressure , that is in the vessels . and they 're going to give information back to the brain . and that 's going to help regulate our blood pressure . now , in this video , we 're actually going to focus on chemoreceptors . chemoreceptors are also important in giving us information , but they 're going to give us information about things like oxygen levels , carbon dioxide levels , ph of the blood , things like that . so these chemoreceptors -- and this gets confusing -- they 're located in a similar region , but not exactly the same region . i 'm actually going to shade in where our chemoreceptors might be , and then also you might get some over here . so these three areas are where chemoreceptors are . and they 're very , of course , closely related to where the baroreceptors are , but they 're actually in slightly different locations . and we call them the aortic body and the carotid body . and the reason we use the term `` body '' is that it 's a body of tissue . so that 's why that word gets used . and this is actually -- you can see now a slightly different location , and certainly a different job . so let me blow up some of these regions and show you , close up , what this might look like . so let me draw for you the carotid body on this side , and on the other side , we 'll do the aortic body . and i 'm basically just zooming in on it , so you can see up close what this might look like , so you can visualize it . so for the carotid body , you might have the external artery , the internal artery . and coming off of the external artery , you might have little branches , little branches serving this tissue that 's in the middle . and these branches , of course , are going to branch some more . and you 're going to get all the way down to the capillary level . and once you have little capillaries in here , there 's going to be a bunch of little cells . and these cells are , of course , going to get the nutrition from the capillary . and taken together , all these cells -- if you zoom out of this picture , this would be a little body of cells or body of tissue . and that 's why we call this the carotid body . and really , the same thing is going on on the aorta side . so on the aorta side , you 've got little branches coming off of the aorta , of course . and these branches are going to branch again , and again , and again , and again . and eventually , you 're going to get lots and lots of little capillaries . and these capillaries are going to serve all these little blue cells that i 'm drawing here , and these are the chemoreceptors that we 're talking about . so these blue cells together make up a body of tissue , and that 's where we get the term `` aortic body '' and `` carotid body . '' now , on the carotid side , one interesting fact is that this body of tissue gets a lot of blood flow , in fact , some of the highest blood flow in the entire human body . it 's about 2 liters per minute for 100 grams . and just to put that in perspective for the carotid body , imagine that you have a little 2-liter bottle of soda . i was thinking of something that would be about 2 liters , and soda came to mind . and you can imagine pouring this soda out over something that 's about 100 grams -- maybe a tomato . that 's about a 100-gram tomato . and if you could do this in one minute , if you could pour out this bottle in one minute , imagine how wet this tomato 's going to get , how much profusion , in a sense , this tomato is going to get . that is how much profusion your carotid body gets . so it really puts it in perspective how much blood flow 's going into that area . so let 's now zoom in a little bit further . let 's say i have a capillary . and inside my capillary , i 've got a little red blood cell here , floating around . and my red blood cell , of course , has some hemoglobin in it , which is a protein . and this protein has got some oxygen bound to it . i 'm going to draw little blue oxygen molecules . and of course , there 's some oxygen out here in the plasma itself as well . and if we 're in our carotid body or aortic body , you might have these special little blue cells that i 've been drawing , our peripheral chemoreceptor cells . and specifically they have a name . these things are called glomus cells . i had initially misstated it as a globus cell . but actually it 's an m -- glomus . and these oxygen molecules -- these are oxygen molecules over here -- are going to diffuse down into the tissue and get into our glomus cell . it 's going to look something like that . and if you have a lot of oxygen in the blood , of course , a lot of molecules are going to diffuse in . but if you do n't have too much in here , then not too much is going to make its way into the cell . and that 's actually the key point . because what our cell is going to be able to do is start to detect low oxygen levels . low oxygen levels in the glomus cell tells this cell that , actually , there are probably low levels in the blood . and when the levels are low , this cell is going to depolarize . its membrane is going to depolarize . and what it has on the other side are little vesicles that are full of neurotransmitter . and so when these vesicles detect that , hey , there 's a depolarization going on , these vesicles are going to dump their neurotransmitter out . and what you have waiting for them is this nice little neuron . so there 's a nice little neuron waiting patiently for a signal , and that signal is going to come in the form of a neurotransmitter . so this is how the communication works . there 's going to be a depolarization , the vessels release their neurotransmitter , and that is going to send an action potential down to our neuron . and if the oxygen levels fall really low , let 's say they get dangerously low , where the cell is very unhappy , then you 're going to get much more neurotransmitter getting dumped out , and you 're going to get many more action potentials . so this is how the glomus cell helps to detect oxygen . and in fact , it also detects carbon dioxide . because , remember , this cell is going to be making carbon dioxide . let 's say this is a little molecule of co2 , and that co2 is going to diffuse out and into the blood . well , let 's say that the blood has a lot of carbon dioxide already . let 's say that it 's loaded with carbon dioxide , lots and lots of it . in this situation , it 's going to be very difficult for carbon dioxide to make its way from the glomus cell all the way out into the plasma . and as a result , carbon dioxide starts building up . the tissue starts gathering more and more co2 , because it ca n't go anywhere . and this glomus cell is going to say , hey , wait a second . our co2 levels are starting to rise . there are high co2 levels . and again , that 's going to make the cell unhappy , and it 's going to send out more neurotransmitter , and it 's going to , of course , send out more action potentials . so two different reasons why you might get action potentials coming out of this glomus cell . and now i want to remind you that there 's this little formula . there 's this formula where carbon dioxide binds with water , and it forms h2co3 . and that 's going to break down into bicarbonate and a proton . so this is our formula . so if co2 levels are rising , like the example i just offered , then the proton level must be high as well . so a high proton concentration -- i 'm going to put it in brackets , to indicate concentration . or another way of saying that would be a low ph . so these are the things that are going to make our glomus cell send off more action potentials . so if you 're like me , you 're thinking , well , wait a second . this is really interesting . our cell is depolarizing . it can depolarize . it also has this neurotransmitter that i mentioned . our glomus cell , then , right here in blue , is basically sounding a little bit like it has properties of a nerve cell . this is a nerve cell . and the reason for that is that , if you actually take a look , these two cells have a common ancestor cell . and so in development , when the fetus is developing , there is a type of tissue called the neuroectoderm . and both of these cells , this nerve cell and this glomus cell , both are derived from this neuroectoderm . so it makes sense that they would have a lot of common features . so we know the glomus cell is not a neuron , but it 's going to be talking to neurons . in fact , you 're going to have many neurons working together in this area . and they 're going to join up , both in the aortic body and the carotid body . and these neurons , going back to the original picture , are going to meet up into a big nerve . and this nerve is going to be called the vagus nerve . the vagus nerve is going to be the one for our aortic body , sometimes also called cranial nerve number 10 . and up here with the carotid body , we have a nerve as well . this is another nerve . this one , we call the glossopharyngeal nerve . so these two nerves , the vagus nerve and the glossopharyngeal nerve -- this one , this glossopharyngeal nerve , by the way , is cranial nerve number 9 -- these two nerves are not part of the brain . they 're headed to the brain , right ? so these two nerves are fundamentally taking information from chemoreceptors that are outside of the brain . they 're not located in the brain , right ? they 're peripheral , and they 're taking information about chemicals and taking that information to the brain . that 's why we call them -- these blue areas , the carotid body and the aortic body -- we call them peripheral chemoreceptors .
|
and if you could do this in one minute , if you could pour out this bottle in one minute , imagine how wet this tomato 's going to get , how much profusion , in a sense , this tomato is going to get . that is how much profusion your carotid body gets . so it really puts it in perspective how much blood flow 's going into that area .
|
for instance , if there was higher amount of circulating 02 ( not bound to hbg because the co is.. ) would the receptors incorrectly perceive this as the body having too much o2 and then communicate to the cns that our o2 level is high ?
|
i 'm going to quickly sketch out the human heart . we 're also going to label some vessels coming off of it . so the big vessel , of course , is the aorta . this is the giant aortic arch . and the aortic arch has a couple of key branches that go , for example , up to the head and neck . it has other branches as well that go out to the arms . but these branches that are going up are the ones i 'm going to focus on . so out here on this right side , we have the right common carotid artery . and it 's called the common because , eventually , what 's going to happen is it 's going to bulge here , and then it 's going to split . and it 's going to split into the internal branch -- this is going inside -- and the external branch over here . so this would be called , for example , the right external carotid artery . and the same thing is happening on the other side , and we name it kind of the same way . we say , ok , there 's an internal branch and an external branch . this would be the internal , and this might be the external branch of the left common carotid artery . so i think you 're getting the idea now . these are named exactly the same way . and these are the ones we 're going to focus on . now , previously , we had talked about how , in these particular locations , in the internal side and then this bulgy side , we have what are called the carotid sinus . or sinuses , i suppose . but the carotid sinus is right there . and the sinus refers to any open area or open space . and there 's also an area over here in the aortic arch . and these two areas , they are the home for our baroreceptors . our baroreceptors are basically little nerves that are going to detect pressure . so they 're going to detect stretch , or pressure , that is in the vessels . and they 're going to give information back to the brain . and that 's going to help regulate our blood pressure . now , in this video , we 're actually going to focus on chemoreceptors . chemoreceptors are also important in giving us information , but they 're going to give us information about things like oxygen levels , carbon dioxide levels , ph of the blood , things like that . so these chemoreceptors -- and this gets confusing -- they 're located in a similar region , but not exactly the same region . i 'm actually going to shade in where our chemoreceptors might be , and then also you might get some over here . so these three areas are where chemoreceptors are . and they 're very , of course , closely related to where the baroreceptors are , but they 're actually in slightly different locations . and we call them the aortic body and the carotid body . and the reason we use the term `` body '' is that it 's a body of tissue . so that 's why that word gets used . and this is actually -- you can see now a slightly different location , and certainly a different job . so let me blow up some of these regions and show you , close up , what this might look like . so let me draw for you the carotid body on this side , and on the other side , we 'll do the aortic body . and i 'm basically just zooming in on it , so you can see up close what this might look like , so you can visualize it . so for the carotid body , you might have the external artery , the internal artery . and coming off of the external artery , you might have little branches , little branches serving this tissue that 's in the middle . and these branches , of course , are going to branch some more . and you 're going to get all the way down to the capillary level . and once you have little capillaries in here , there 's going to be a bunch of little cells . and these cells are , of course , going to get the nutrition from the capillary . and taken together , all these cells -- if you zoom out of this picture , this would be a little body of cells or body of tissue . and that 's why we call this the carotid body . and really , the same thing is going on on the aorta side . so on the aorta side , you 've got little branches coming off of the aorta , of course . and these branches are going to branch again , and again , and again , and again . and eventually , you 're going to get lots and lots of little capillaries . and these capillaries are going to serve all these little blue cells that i 'm drawing here , and these are the chemoreceptors that we 're talking about . so these blue cells together make up a body of tissue , and that 's where we get the term `` aortic body '' and `` carotid body . '' now , on the carotid side , one interesting fact is that this body of tissue gets a lot of blood flow , in fact , some of the highest blood flow in the entire human body . it 's about 2 liters per minute for 100 grams . and just to put that in perspective for the carotid body , imagine that you have a little 2-liter bottle of soda . i was thinking of something that would be about 2 liters , and soda came to mind . and you can imagine pouring this soda out over something that 's about 100 grams -- maybe a tomato . that 's about a 100-gram tomato . and if you could do this in one minute , if you could pour out this bottle in one minute , imagine how wet this tomato 's going to get , how much profusion , in a sense , this tomato is going to get . that is how much profusion your carotid body gets . so it really puts it in perspective how much blood flow 's going into that area . so let 's now zoom in a little bit further . let 's say i have a capillary . and inside my capillary , i 've got a little red blood cell here , floating around . and my red blood cell , of course , has some hemoglobin in it , which is a protein . and this protein has got some oxygen bound to it . i 'm going to draw little blue oxygen molecules . and of course , there 's some oxygen out here in the plasma itself as well . and if we 're in our carotid body or aortic body , you might have these special little blue cells that i 've been drawing , our peripheral chemoreceptor cells . and specifically they have a name . these things are called glomus cells . i had initially misstated it as a globus cell . but actually it 's an m -- glomus . and these oxygen molecules -- these are oxygen molecules over here -- are going to diffuse down into the tissue and get into our glomus cell . it 's going to look something like that . and if you have a lot of oxygen in the blood , of course , a lot of molecules are going to diffuse in . but if you do n't have too much in here , then not too much is going to make its way into the cell . and that 's actually the key point . because what our cell is going to be able to do is start to detect low oxygen levels . low oxygen levels in the glomus cell tells this cell that , actually , there are probably low levels in the blood . and when the levels are low , this cell is going to depolarize . its membrane is going to depolarize . and what it has on the other side are little vesicles that are full of neurotransmitter . and so when these vesicles detect that , hey , there 's a depolarization going on , these vesicles are going to dump their neurotransmitter out . and what you have waiting for them is this nice little neuron . so there 's a nice little neuron waiting patiently for a signal , and that signal is going to come in the form of a neurotransmitter . so this is how the communication works . there 's going to be a depolarization , the vessels release their neurotransmitter , and that is going to send an action potential down to our neuron . and if the oxygen levels fall really low , let 's say they get dangerously low , where the cell is very unhappy , then you 're going to get much more neurotransmitter getting dumped out , and you 're going to get many more action potentials . so this is how the glomus cell helps to detect oxygen . and in fact , it also detects carbon dioxide . because , remember , this cell is going to be making carbon dioxide . let 's say this is a little molecule of co2 , and that co2 is going to diffuse out and into the blood . well , let 's say that the blood has a lot of carbon dioxide already . let 's say that it 's loaded with carbon dioxide , lots and lots of it . in this situation , it 's going to be very difficult for carbon dioxide to make its way from the glomus cell all the way out into the plasma . and as a result , carbon dioxide starts building up . the tissue starts gathering more and more co2 , because it ca n't go anywhere . and this glomus cell is going to say , hey , wait a second . our co2 levels are starting to rise . there are high co2 levels . and again , that 's going to make the cell unhappy , and it 's going to send out more neurotransmitter , and it 's going to , of course , send out more action potentials . so two different reasons why you might get action potentials coming out of this glomus cell . and now i want to remind you that there 's this little formula . there 's this formula where carbon dioxide binds with water , and it forms h2co3 . and that 's going to break down into bicarbonate and a proton . so this is our formula . so if co2 levels are rising , like the example i just offered , then the proton level must be high as well . so a high proton concentration -- i 'm going to put it in brackets , to indicate concentration . or another way of saying that would be a low ph . so these are the things that are going to make our glomus cell send off more action potentials . so if you 're like me , you 're thinking , well , wait a second . this is really interesting . our cell is depolarizing . it can depolarize . it also has this neurotransmitter that i mentioned . our glomus cell , then , right here in blue , is basically sounding a little bit like it has properties of a nerve cell . this is a nerve cell . and the reason for that is that , if you actually take a look , these two cells have a common ancestor cell . and so in development , when the fetus is developing , there is a type of tissue called the neuroectoderm . and both of these cells , this nerve cell and this glomus cell , both are derived from this neuroectoderm . so it makes sense that they would have a lot of common features . so we know the glomus cell is not a neuron , but it 's going to be talking to neurons . in fact , you 're going to have many neurons working together in this area . and they 're going to join up , both in the aortic body and the carotid body . and these neurons , going back to the original picture , are going to meet up into a big nerve . and this nerve is going to be called the vagus nerve . the vagus nerve is going to be the one for our aortic body , sometimes also called cranial nerve number 10 . and up here with the carotid body , we have a nerve as well . this is another nerve . this one , we call the glossopharyngeal nerve . so these two nerves , the vagus nerve and the glossopharyngeal nerve -- this one , this glossopharyngeal nerve , by the way , is cranial nerve number 9 -- these two nerves are not part of the brain . they 're headed to the brain , right ? so these two nerves are fundamentally taking information from chemoreceptors that are outside of the brain . they 're not located in the brain , right ? they 're peripheral , and they 're taking information about chemicals and taking that information to the brain . that 's why we call them -- these blue areas , the carotid body and the aortic body -- we call them peripheral chemoreceptors .
|
these things are called glomus cells . i had initially misstated it as a globus cell . but actually it 's an m -- glomus .
|
does the globus cell die when it depolarizes and releases its neurotransmitters ?
|
i 'm going to quickly sketch out the human heart . we 're also going to label some vessels coming off of it . so the big vessel , of course , is the aorta . this is the giant aortic arch . and the aortic arch has a couple of key branches that go , for example , up to the head and neck . it has other branches as well that go out to the arms . but these branches that are going up are the ones i 'm going to focus on . so out here on this right side , we have the right common carotid artery . and it 's called the common because , eventually , what 's going to happen is it 's going to bulge here , and then it 's going to split . and it 's going to split into the internal branch -- this is going inside -- and the external branch over here . so this would be called , for example , the right external carotid artery . and the same thing is happening on the other side , and we name it kind of the same way . we say , ok , there 's an internal branch and an external branch . this would be the internal , and this might be the external branch of the left common carotid artery . so i think you 're getting the idea now . these are named exactly the same way . and these are the ones we 're going to focus on . now , previously , we had talked about how , in these particular locations , in the internal side and then this bulgy side , we have what are called the carotid sinus . or sinuses , i suppose . but the carotid sinus is right there . and the sinus refers to any open area or open space . and there 's also an area over here in the aortic arch . and these two areas , they are the home for our baroreceptors . our baroreceptors are basically little nerves that are going to detect pressure . so they 're going to detect stretch , or pressure , that is in the vessels . and they 're going to give information back to the brain . and that 's going to help regulate our blood pressure . now , in this video , we 're actually going to focus on chemoreceptors . chemoreceptors are also important in giving us information , but they 're going to give us information about things like oxygen levels , carbon dioxide levels , ph of the blood , things like that . so these chemoreceptors -- and this gets confusing -- they 're located in a similar region , but not exactly the same region . i 'm actually going to shade in where our chemoreceptors might be , and then also you might get some over here . so these three areas are where chemoreceptors are . and they 're very , of course , closely related to where the baroreceptors are , but they 're actually in slightly different locations . and we call them the aortic body and the carotid body . and the reason we use the term `` body '' is that it 's a body of tissue . so that 's why that word gets used . and this is actually -- you can see now a slightly different location , and certainly a different job . so let me blow up some of these regions and show you , close up , what this might look like . so let me draw for you the carotid body on this side , and on the other side , we 'll do the aortic body . and i 'm basically just zooming in on it , so you can see up close what this might look like , so you can visualize it . so for the carotid body , you might have the external artery , the internal artery . and coming off of the external artery , you might have little branches , little branches serving this tissue that 's in the middle . and these branches , of course , are going to branch some more . and you 're going to get all the way down to the capillary level . and once you have little capillaries in here , there 's going to be a bunch of little cells . and these cells are , of course , going to get the nutrition from the capillary . and taken together , all these cells -- if you zoom out of this picture , this would be a little body of cells or body of tissue . and that 's why we call this the carotid body . and really , the same thing is going on on the aorta side . so on the aorta side , you 've got little branches coming off of the aorta , of course . and these branches are going to branch again , and again , and again , and again . and eventually , you 're going to get lots and lots of little capillaries . and these capillaries are going to serve all these little blue cells that i 'm drawing here , and these are the chemoreceptors that we 're talking about . so these blue cells together make up a body of tissue , and that 's where we get the term `` aortic body '' and `` carotid body . '' now , on the carotid side , one interesting fact is that this body of tissue gets a lot of blood flow , in fact , some of the highest blood flow in the entire human body . it 's about 2 liters per minute for 100 grams . and just to put that in perspective for the carotid body , imagine that you have a little 2-liter bottle of soda . i was thinking of something that would be about 2 liters , and soda came to mind . and you can imagine pouring this soda out over something that 's about 100 grams -- maybe a tomato . that 's about a 100-gram tomato . and if you could do this in one minute , if you could pour out this bottle in one minute , imagine how wet this tomato 's going to get , how much profusion , in a sense , this tomato is going to get . that is how much profusion your carotid body gets . so it really puts it in perspective how much blood flow 's going into that area . so let 's now zoom in a little bit further . let 's say i have a capillary . and inside my capillary , i 've got a little red blood cell here , floating around . and my red blood cell , of course , has some hemoglobin in it , which is a protein . and this protein has got some oxygen bound to it . i 'm going to draw little blue oxygen molecules . and of course , there 's some oxygen out here in the plasma itself as well . and if we 're in our carotid body or aortic body , you might have these special little blue cells that i 've been drawing , our peripheral chemoreceptor cells . and specifically they have a name . these things are called glomus cells . i had initially misstated it as a globus cell . but actually it 's an m -- glomus . and these oxygen molecules -- these are oxygen molecules over here -- are going to diffuse down into the tissue and get into our glomus cell . it 's going to look something like that . and if you have a lot of oxygen in the blood , of course , a lot of molecules are going to diffuse in . but if you do n't have too much in here , then not too much is going to make its way into the cell . and that 's actually the key point . because what our cell is going to be able to do is start to detect low oxygen levels . low oxygen levels in the glomus cell tells this cell that , actually , there are probably low levels in the blood . and when the levels are low , this cell is going to depolarize . its membrane is going to depolarize . and what it has on the other side are little vesicles that are full of neurotransmitter . and so when these vesicles detect that , hey , there 's a depolarization going on , these vesicles are going to dump their neurotransmitter out . and what you have waiting for them is this nice little neuron . so there 's a nice little neuron waiting patiently for a signal , and that signal is going to come in the form of a neurotransmitter . so this is how the communication works . there 's going to be a depolarization , the vessels release their neurotransmitter , and that is going to send an action potential down to our neuron . and if the oxygen levels fall really low , let 's say they get dangerously low , where the cell is very unhappy , then you 're going to get much more neurotransmitter getting dumped out , and you 're going to get many more action potentials . so this is how the glomus cell helps to detect oxygen . and in fact , it also detects carbon dioxide . because , remember , this cell is going to be making carbon dioxide . let 's say this is a little molecule of co2 , and that co2 is going to diffuse out and into the blood . well , let 's say that the blood has a lot of carbon dioxide already . let 's say that it 's loaded with carbon dioxide , lots and lots of it . in this situation , it 's going to be very difficult for carbon dioxide to make its way from the glomus cell all the way out into the plasma . and as a result , carbon dioxide starts building up . the tissue starts gathering more and more co2 , because it ca n't go anywhere . and this glomus cell is going to say , hey , wait a second . our co2 levels are starting to rise . there are high co2 levels . and again , that 's going to make the cell unhappy , and it 's going to send out more neurotransmitter , and it 's going to , of course , send out more action potentials . so two different reasons why you might get action potentials coming out of this glomus cell . and now i want to remind you that there 's this little formula . there 's this formula where carbon dioxide binds with water , and it forms h2co3 . and that 's going to break down into bicarbonate and a proton . so this is our formula . so if co2 levels are rising , like the example i just offered , then the proton level must be high as well . so a high proton concentration -- i 'm going to put it in brackets , to indicate concentration . or another way of saying that would be a low ph . so these are the things that are going to make our glomus cell send off more action potentials . so if you 're like me , you 're thinking , well , wait a second . this is really interesting . our cell is depolarizing . it can depolarize . it also has this neurotransmitter that i mentioned . our glomus cell , then , right here in blue , is basically sounding a little bit like it has properties of a nerve cell . this is a nerve cell . and the reason for that is that , if you actually take a look , these two cells have a common ancestor cell . and so in development , when the fetus is developing , there is a type of tissue called the neuroectoderm . and both of these cells , this nerve cell and this glomus cell , both are derived from this neuroectoderm . so it makes sense that they would have a lot of common features . so we know the glomus cell is not a neuron , but it 's going to be talking to neurons . in fact , you 're going to have many neurons working together in this area . and they 're going to join up , both in the aortic body and the carotid body . and these neurons , going back to the original picture , are going to meet up into a big nerve . and this nerve is going to be called the vagus nerve . the vagus nerve is going to be the one for our aortic body , sometimes also called cranial nerve number 10 . and up here with the carotid body , we have a nerve as well . this is another nerve . this one , we call the glossopharyngeal nerve . so these two nerves , the vagus nerve and the glossopharyngeal nerve -- this one , this glossopharyngeal nerve , by the way , is cranial nerve number 9 -- these two nerves are not part of the brain . they 're headed to the brain , right ? so these two nerves are fundamentally taking information from chemoreceptors that are outside of the brain . they 're not located in the brain , right ? they 're peripheral , and they 're taking information about chemicals and taking that information to the brain . that 's why we call them -- these blue areas , the carotid body and the aortic body -- we call them peripheral chemoreceptors .
|
and my red blood cell , of course , has some hemoglobin in it , which is a protein . and this protein has got some oxygen bound to it . i 'm going to draw little blue oxygen molecules . and of course , there 's some oxygen out here in the plasma itself as well .
|
the cell lets the neurotransmitter know there is too little oxygen , so what happens on the cellular level when there is too much oxygen ?
|
i 'm going to quickly sketch out the human heart . we 're also going to label some vessels coming off of it . so the big vessel , of course , is the aorta . this is the giant aortic arch . and the aortic arch has a couple of key branches that go , for example , up to the head and neck . it has other branches as well that go out to the arms . but these branches that are going up are the ones i 'm going to focus on . so out here on this right side , we have the right common carotid artery . and it 's called the common because , eventually , what 's going to happen is it 's going to bulge here , and then it 's going to split . and it 's going to split into the internal branch -- this is going inside -- and the external branch over here . so this would be called , for example , the right external carotid artery . and the same thing is happening on the other side , and we name it kind of the same way . we say , ok , there 's an internal branch and an external branch . this would be the internal , and this might be the external branch of the left common carotid artery . so i think you 're getting the idea now . these are named exactly the same way . and these are the ones we 're going to focus on . now , previously , we had talked about how , in these particular locations , in the internal side and then this bulgy side , we have what are called the carotid sinus . or sinuses , i suppose . but the carotid sinus is right there . and the sinus refers to any open area or open space . and there 's also an area over here in the aortic arch . and these two areas , they are the home for our baroreceptors . our baroreceptors are basically little nerves that are going to detect pressure . so they 're going to detect stretch , or pressure , that is in the vessels . and they 're going to give information back to the brain . and that 's going to help regulate our blood pressure . now , in this video , we 're actually going to focus on chemoreceptors . chemoreceptors are also important in giving us information , but they 're going to give us information about things like oxygen levels , carbon dioxide levels , ph of the blood , things like that . so these chemoreceptors -- and this gets confusing -- they 're located in a similar region , but not exactly the same region . i 'm actually going to shade in where our chemoreceptors might be , and then also you might get some over here . so these three areas are where chemoreceptors are . and they 're very , of course , closely related to where the baroreceptors are , but they 're actually in slightly different locations . and we call them the aortic body and the carotid body . and the reason we use the term `` body '' is that it 's a body of tissue . so that 's why that word gets used . and this is actually -- you can see now a slightly different location , and certainly a different job . so let me blow up some of these regions and show you , close up , what this might look like . so let me draw for you the carotid body on this side , and on the other side , we 'll do the aortic body . and i 'm basically just zooming in on it , so you can see up close what this might look like , so you can visualize it . so for the carotid body , you might have the external artery , the internal artery . and coming off of the external artery , you might have little branches , little branches serving this tissue that 's in the middle . and these branches , of course , are going to branch some more . and you 're going to get all the way down to the capillary level . and once you have little capillaries in here , there 's going to be a bunch of little cells . and these cells are , of course , going to get the nutrition from the capillary . and taken together , all these cells -- if you zoom out of this picture , this would be a little body of cells or body of tissue . and that 's why we call this the carotid body . and really , the same thing is going on on the aorta side . so on the aorta side , you 've got little branches coming off of the aorta , of course . and these branches are going to branch again , and again , and again , and again . and eventually , you 're going to get lots and lots of little capillaries . and these capillaries are going to serve all these little blue cells that i 'm drawing here , and these are the chemoreceptors that we 're talking about . so these blue cells together make up a body of tissue , and that 's where we get the term `` aortic body '' and `` carotid body . '' now , on the carotid side , one interesting fact is that this body of tissue gets a lot of blood flow , in fact , some of the highest blood flow in the entire human body . it 's about 2 liters per minute for 100 grams . and just to put that in perspective for the carotid body , imagine that you have a little 2-liter bottle of soda . i was thinking of something that would be about 2 liters , and soda came to mind . and you can imagine pouring this soda out over something that 's about 100 grams -- maybe a tomato . that 's about a 100-gram tomato . and if you could do this in one minute , if you could pour out this bottle in one minute , imagine how wet this tomato 's going to get , how much profusion , in a sense , this tomato is going to get . that is how much profusion your carotid body gets . so it really puts it in perspective how much blood flow 's going into that area . so let 's now zoom in a little bit further . let 's say i have a capillary . and inside my capillary , i 've got a little red blood cell here , floating around . and my red blood cell , of course , has some hemoglobin in it , which is a protein . and this protein has got some oxygen bound to it . i 'm going to draw little blue oxygen molecules . and of course , there 's some oxygen out here in the plasma itself as well . and if we 're in our carotid body or aortic body , you might have these special little blue cells that i 've been drawing , our peripheral chemoreceptor cells . and specifically they have a name . these things are called glomus cells . i had initially misstated it as a globus cell . but actually it 's an m -- glomus . and these oxygen molecules -- these are oxygen molecules over here -- are going to diffuse down into the tissue and get into our glomus cell . it 's going to look something like that . and if you have a lot of oxygen in the blood , of course , a lot of molecules are going to diffuse in . but if you do n't have too much in here , then not too much is going to make its way into the cell . and that 's actually the key point . because what our cell is going to be able to do is start to detect low oxygen levels . low oxygen levels in the glomus cell tells this cell that , actually , there are probably low levels in the blood . and when the levels are low , this cell is going to depolarize . its membrane is going to depolarize . and what it has on the other side are little vesicles that are full of neurotransmitter . and so when these vesicles detect that , hey , there 's a depolarization going on , these vesicles are going to dump their neurotransmitter out . and what you have waiting for them is this nice little neuron . so there 's a nice little neuron waiting patiently for a signal , and that signal is going to come in the form of a neurotransmitter . so this is how the communication works . there 's going to be a depolarization , the vessels release their neurotransmitter , and that is going to send an action potential down to our neuron . and if the oxygen levels fall really low , let 's say they get dangerously low , where the cell is very unhappy , then you 're going to get much more neurotransmitter getting dumped out , and you 're going to get many more action potentials . so this is how the glomus cell helps to detect oxygen . and in fact , it also detects carbon dioxide . because , remember , this cell is going to be making carbon dioxide . let 's say this is a little molecule of co2 , and that co2 is going to diffuse out and into the blood . well , let 's say that the blood has a lot of carbon dioxide already . let 's say that it 's loaded with carbon dioxide , lots and lots of it . in this situation , it 's going to be very difficult for carbon dioxide to make its way from the glomus cell all the way out into the plasma . and as a result , carbon dioxide starts building up . the tissue starts gathering more and more co2 , because it ca n't go anywhere . and this glomus cell is going to say , hey , wait a second . our co2 levels are starting to rise . there are high co2 levels . and again , that 's going to make the cell unhappy , and it 's going to send out more neurotransmitter , and it 's going to , of course , send out more action potentials . so two different reasons why you might get action potentials coming out of this glomus cell . and now i want to remind you that there 's this little formula . there 's this formula where carbon dioxide binds with water , and it forms h2co3 . and that 's going to break down into bicarbonate and a proton . so this is our formula . so if co2 levels are rising , like the example i just offered , then the proton level must be high as well . so a high proton concentration -- i 'm going to put it in brackets , to indicate concentration . or another way of saying that would be a low ph . so these are the things that are going to make our glomus cell send off more action potentials . so if you 're like me , you 're thinking , well , wait a second . this is really interesting . our cell is depolarizing . it can depolarize . it also has this neurotransmitter that i mentioned . our glomus cell , then , right here in blue , is basically sounding a little bit like it has properties of a nerve cell . this is a nerve cell . and the reason for that is that , if you actually take a look , these two cells have a common ancestor cell . and so in development , when the fetus is developing , there is a type of tissue called the neuroectoderm . and both of these cells , this nerve cell and this glomus cell , both are derived from this neuroectoderm . so it makes sense that they would have a lot of common features . so we know the glomus cell is not a neuron , but it 's going to be talking to neurons . in fact , you 're going to have many neurons working together in this area . and they 're going to join up , both in the aortic body and the carotid body . and these neurons , going back to the original picture , are going to meet up into a big nerve . and this nerve is going to be called the vagus nerve . the vagus nerve is going to be the one for our aortic body , sometimes also called cranial nerve number 10 . and up here with the carotid body , we have a nerve as well . this is another nerve . this one , we call the glossopharyngeal nerve . so these two nerves , the vagus nerve and the glossopharyngeal nerve -- this one , this glossopharyngeal nerve , by the way , is cranial nerve number 9 -- these two nerves are not part of the brain . they 're headed to the brain , right ? so these two nerves are fundamentally taking information from chemoreceptors that are outside of the brain . they 're not located in the brain , right ? they 're peripheral , and they 're taking information about chemicals and taking that information to the brain . that 's why we call them -- these blue areas , the carotid body and the aortic body -- we call them peripheral chemoreceptors .
|
so this is how the glomus cell helps to detect oxygen . and in fact , it also detects carbon dioxide . because , remember , this cell is going to be making carbon dioxide .
|
also are there any problems when there is very low amounts of carbon dioxide ?
|
i 'm going to quickly sketch out the human heart . we 're also going to label some vessels coming off of it . so the big vessel , of course , is the aorta . this is the giant aortic arch . and the aortic arch has a couple of key branches that go , for example , up to the head and neck . it has other branches as well that go out to the arms . but these branches that are going up are the ones i 'm going to focus on . so out here on this right side , we have the right common carotid artery . and it 's called the common because , eventually , what 's going to happen is it 's going to bulge here , and then it 's going to split . and it 's going to split into the internal branch -- this is going inside -- and the external branch over here . so this would be called , for example , the right external carotid artery . and the same thing is happening on the other side , and we name it kind of the same way . we say , ok , there 's an internal branch and an external branch . this would be the internal , and this might be the external branch of the left common carotid artery . so i think you 're getting the idea now . these are named exactly the same way . and these are the ones we 're going to focus on . now , previously , we had talked about how , in these particular locations , in the internal side and then this bulgy side , we have what are called the carotid sinus . or sinuses , i suppose . but the carotid sinus is right there . and the sinus refers to any open area or open space . and there 's also an area over here in the aortic arch . and these two areas , they are the home for our baroreceptors . our baroreceptors are basically little nerves that are going to detect pressure . so they 're going to detect stretch , or pressure , that is in the vessels . and they 're going to give information back to the brain . and that 's going to help regulate our blood pressure . now , in this video , we 're actually going to focus on chemoreceptors . chemoreceptors are also important in giving us information , but they 're going to give us information about things like oxygen levels , carbon dioxide levels , ph of the blood , things like that . so these chemoreceptors -- and this gets confusing -- they 're located in a similar region , but not exactly the same region . i 'm actually going to shade in where our chemoreceptors might be , and then also you might get some over here . so these three areas are where chemoreceptors are . and they 're very , of course , closely related to where the baroreceptors are , but they 're actually in slightly different locations . and we call them the aortic body and the carotid body . and the reason we use the term `` body '' is that it 's a body of tissue . so that 's why that word gets used . and this is actually -- you can see now a slightly different location , and certainly a different job . so let me blow up some of these regions and show you , close up , what this might look like . so let me draw for you the carotid body on this side , and on the other side , we 'll do the aortic body . and i 'm basically just zooming in on it , so you can see up close what this might look like , so you can visualize it . so for the carotid body , you might have the external artery , the internal artery . and coming off of the external artery , you might have little branches , little branches serving this tissue that 's in the middle . and these branches , of course , are going to branch some more . and you 're going to get all the way down to the capillary level . and once you have little capillaries in here , there 's going to be a bunch of little cells . and these cells are , of course , going to get the nutrition from the capillary . and taken together , all these cells -- if you zoom out of this picture , this would be a little body of cells or body of tissue . and that 's why we call this the carotid body . and really , the same thing is going on on the aorta side . so on the aorta side , you 've got little branches coming off of the aorta , of course . and these branches are going to branch again , and again , and again , and again . and eventually , you 're going to get lots and lots of little capillaries . and these capillaries are going to serve all these little blue cells that i 'm drawing here , and these are the chemoreceptors that we 're talking about . so these blue cells together make up a body of tissue , and that 's where we get the term `` aortic body '' and `` carotid body . '' now , on the carotid side , one interesting fact is that this body of tissue gets a lot of blood flow , in fact , some of the highest blood flow in the entire human body . it 's about 2 liters per minute for 100 grams . and just to put that in perspective for the carotid body , imagine that you have a little 2-liter bottle of soda . i was thinking of something that would be about 2 liters , and soda came to mind . and you can imagine pouring this soda out over something that 's about 100 grams -- maybe a tomato . that 's about a 100-gram tomato . and if you could do this in one minute , if you could pour out this bottle in one minute , imagine how wet this tomato 's going to get , how much profusion , in a sense , this tomato is going to get . that is how much profusion your carotid body gets . so it really puts it in perspective how much blood flow 's going into that area . so let 's now zoom in a little bit further . let 's say i have a capillary . and inside my capillary , i 've got a little red blood cell here , floating around . and my red blood cell , of course , has some hemoglobin in it , which is a protein . and this protein has got some oxygen bound to it . i 'm going to draw little blue oxygen molecules . and of course , there 's some oxygen out here in the plasma itself as well . and if we 're in our carotid body or aortic body , you might have these special little blue cells that i 've been drawing , our peripheral chemoreceptor cells . and specifically they have a name . these things are called glomus cells . i had initially misstated it as a globus cell . but actually it 's an m -- glomus . and these oxygen molecules -- these are oxygen molecules over here -- are going to diffuse down into the tissue and get into our glomus cell . it 's going to look something like that . and if you have a lot of oxygen in the blood , of course , a lot of molecules are going to diffuse in . but if you do n't have too much in here , then not too much is going to make its way into the cell . and that 's actually the key point . because what our cell is going to be able to do is start to detect low oxygen levels . low oxygen levels in the glomus cell tells this cell that , actually , there are probably low levels in the blood . and when the levels are low , this cell is going to depolarize . its membrane is going to depolarize . and what it has on the other side are little vesicles that are full of neurotransmitter . and so when these vesicles detect that , hey , there 's a depolarization going on , these vesicles are going to dump their neurotransmitter out . and what you have waiting for them is this nice little neuron . so there 's a nice little neuron waiting patiently for a signal , and that signal is going to come in the form of a neurotransmitter . so this is how the communication works . there 's going to be a depolarization , the vessels release their neurotransmitter , and that is going to send an action potential down to our neuron . and if the oxygen levels fall really low , let 's say they get dangerously low , where the cell is very unhappy , then you 're going to get much more neurotransmitter getting dumped out , and you 're going to get many more action potentials . so this is how the glomus cell helps to detect oxygen . and in fact , it also detects carbon dioxide . because , remember , this cell is going to be making carbon dioxide . let 's say this is a little molecule of co2 , and that co2 is going to diffuse out and into the blood . well , let 's say that the blood has a lot of carbon dioxide already . let 's say that it 's loaded with carbon dioxide , lots and lots of it . in this situation , it 's going to be very difficult for carbon dioxide to make its way from the glomus cell all the way out into the plasma . and as a result , carbon dioxide starts building up . the tissue starts gathering more and more co2 , because it ca n't go anywhere . and this glomus cell is going to say , hey , wait a second . our co2 levels are starting to rise . there are high co2 levels . and again , that 's going to make the cell unhappy , and it 's going to send out more neurotransmitter , and it 's going to , of course , send out more action potentials . so two different reasons why you might get action potentials coming out of this glomus cell . and now i want to remind you that there 's this little formula . there 's this formula where carbon dioxide binds with water , and it forms h2co3 . and that 's going to break down into bicarbonate and a proton . so this is our formula . so if co2 levels are rising , like the example i just offered , then the proton level must be high as well . so a high proton concentration -- i 'm going to put it in brackets , to indicate concentration . or another way of saying that would be a low ph . so these are the things that are going to make our glomus cell send off more action potentials . so if you 're like me , you 're thinking , well , wait a second . this is really interesting . our cell is depolarizing . it can depolarize . it also has this neurotransmitter that i mentioned . our glomus cell , then , right here in blue , is basically sounding a little bit like it has properties of a nerve cell . this is a nerve cell . and the reason for that is that , if you actually take a look , these two cells have a common ancestor cell . and so in development , when the fetus is developing , there is a type of tissue called the neuroectoderm . and both of these cells , this nerve cell and this glomus cell , both are derived from this neuroectoderm . so it makes sense that they would have a lot of common features . so we know the glomus cell is not a neuron , but it 's going to be talking to neurons . in fact , you 're going to have many neurons working together in this area . and they 're going to join up , both in the aortic body and the carotid body . and these neurons , going back to the original picture , are going to meet up into a big nerve . and this nerve is going to be called the vagus nerve . the vagus nerve is going to be the one for our aortic body , sometimes also called cranial nerve number 10 . and up here with the carotid body , we have a nerve as well . this is another nerve . this one , we call the glossopharyngeal nerve . so these two nerves , the vagus nerve and the glossopharyngeal nerve -- this one , this glossopharyngeal nerve , by the way , is cranial nerve number 9 -- these two nerves are not part of the brain . they 're headed to the brain , right ? so these two nerves are fundamentally taking information from chemoreceptors that are outside of the brain . they 're not located in the brain , right ? they 're peripheral , and they 're taking information about chemicals and taking that information to the brain . that 's why we call them -- these blue areas , the carotid body and the aortic body -- we call them peripheral chemoreceptors .
|
because what our cell is going to be able to do is start to detect low oxygen levels . low oxygen levels in the glomus cell tells this cell that , actually , there are probably low levels in the blood . and when the levels are low , this cell is going to depolarize .
|
would the heart be considered the organ that measures the oxygen levels in our blood or would that be the kidney ?
|
i 'm going to quickly sketch out the human heart . we 're also going to label some vessels coming off of it . so the big vessel , of course , is the aorta . this is the giant aortic arch . and the aortic arch has a couple of key branches that go , for example , up to the head and neck . it has other branches as well that go out to the arms . but these branches that are going up are the ones i 'm going to focus on . so out here on this right side , we have the right common carotid artery . and it 's called the common because , eventually , what 's going to happen is it 's going to bulge here , and then it 's going to split . and it 's going to split into the internal branch -- this is going inside -- and the external branch over here . so this would be called , for example , the right external carotid artery . and the same thing is happening on the other side , and we name it kind of the same way . we say , ok , there 's an internal branch and an external branch . this would be the internal , and this might be the external branch of the left common carotid artery . so i think you 're getting the idea now . these are named exactly the same way . and these are the ones we 're going to focus on . now , previously , we had talked about how , in these particular locations , in the internal side and then this bulgy side , we have what are called the carotid sinus . or sinuses , i suppose . but the carotid sinus is right there . and the sinus refers to any open area or open space . and there 's also an area over here in the aortic arch . and these two areas , they are the home for our baroreceptors . our baroreceptors are basically little nerves that are going to detect pressure . so they 're going to detect stretch , or pressure , that is in the vessels . and they 're going to give information back to the brain . and that 's going to help regulate our blood pressure . now , in this video , we 're actually going to focus on chemoreceptors . chemoreceptors are also important in giving us information , but they 're going to give us information about things like oxygen levels , carbon dioxide levels , ph of the blood , things like that . so these chemoreceptors -- and this gets confusing -- they 're located in a similar region , but not exactly the same region . i 'm actually going to shade in where our chemoreceptors might be , and then also you might get some over here . so these three areas are where chemoreceptors are . and they 're very , of course , closely related to where the baroreceptors are , but they 're actually in slightly different locations . and we call them the aortic body and the carotid body . and the reason we use the term `` body '' is that it 's a body of tissue . so that 's why that word gets used . and this is actually -- you can see now a slightly different location , and certainly a different job . so let me blow up some of these regions and show you , close up , what this might look like . so let me draw for you the carotid body on this side , and on the other side , we 'll do the aortic body . and i 'm basically just zooming in on it , so you can see up close what this might look like , so you can visualize it . so for the carotid body , you might have the external artery , the internal artery . and coming off of the external artery , you might have little branches , little branches serving this tissue that 's in the middle . and these branches , of course , are going to branch some more . and you 're going to get all the way down to the capillary level . and once you have little capillaries in here , there 's going to be a bunch of little cells . and these cells are , of course , going to get the nutrition from the capillary . and taken together , all these cells -- if you zoom out of this picture , this would be a little body of cells or body of tissue . and that 's why we call this the carotid body . and really , the same thing is going on on the aorta side . so on the aorta side , you 've got little branches coming off of the aorta , of course . and these branches are going to branch again , and again , and again , and again . and eventually , you 're going to get lots and lots of little capillaries . and these capillaries are going to serve all these little blue cells that i 'm drawing here , and these are the chemoreceptors that we 're talking about . so these blue cells together make up a body of tissue , and that 's where we get the term `` aortic body '' and `` carotid body . '' now , on the carotid side , one interesting fact is that this body of tissue gets a lot of blood flow , in fact , some of the highest blood flow in the entire human body . it 's about 2 liters per minute for 100 grams . and just to put that in perspective for the carotid body , imagine that you have a little 2-liter bottle of soda . i was thinking of something that would be about 2 liters , and soda came to mind . and you can imagine pouring this soda out over something that 's about 100 grams -- maybe a tomato . that 's about a 100-gram tomato . and if you could do this in one minute , if you could pour out this bottle in one minute , imagine how wet this tomato 's going to get , how much profusion , in a sense , this tomato is going to get . that is how much profusion your carotid body gets . so it really puts it in perspective how much blood flow 's going into that area . so let 's now zoom in a little bit further . let 's say i have a capillary . and inside my capillary , i 've got a little red blood cell here , floating around . and my red blood cell , of course , has some hemoglobin in it , which is a protein . and this protein has got some oxygen bound to it . i 'm going to draw little blue oxygen molecules . and of course , there 's some oxygen out here in the plasma itself as well . and if we 're in our carotid body or aortic body , you might have these special little blue cells that i 've been drawing , our peripheral chemoreceptor cells . and specifically they have a name . these things are called glomus cells . i had initially misstated it as a globus cell . but actually it 's an m -- glomus . and these oxygen molecules -- these are oxygen molecules over here -- are going to diffuse down into the tissue and get into our glomus cell . it 's going to look something like that . and if you have a lot of oxygen in the blood , of course , a lot of molecules are going to diffuse in . but if you do n't have too much in here , then not too much is going to make its way into the cell . and that 's actually the key point . because what our cell is going to be able to do is start to detect low oxygen levels . low oxygen levels in the glomus cell tells this cell that , actually , there are probably low levels in the blood . and when the levels are low , this cell is going to depolarize . its membrane is going to depolarize . and what it has on the other side are little vesicles that are full of neurotransmitter . and so when these vesicles detect that , hey , there 's a depolarization going on , these vesicles are going to dump their neurotransmitter out . and what you have waiting for them is this nice little neuron . so there 's a nice little neuron waiting patiently for a signal , and that signal is going to come in the form of a neurotransmitter . so this is how the communication works . there 's going to be a depolarization , the vessels release their neurotransmitter , and that is going to send an action potential down to our neuron . and if the oxygen levels fall really low , let 's say they get dangerously low , where the cell is very unhappy , then you 're going to get much more neurotransmitter getting dumped out , and you 're going to get many more action potentials . so this is how the glomus cell helps to detect oxygen . and in fact , it also detects carbon dioxide . because , remember , this cell is going to be making carbon dioxide . let 's say this is a little molecule of co2 , and that co2 is going to diffuse out and into the blood . well , let 's say that the blood has a lot of carbon dioxide already . let 's say that it 's loaded with carbon dioxide , lots and lots of it . in this situation , it 's going to be very difficult for carbon dioxide to make its way from the glomus cell all the way out into the plasma . and as a result , carbon dioxide starts building up . the tissue starts gathering more and more co2 , because it ca n't go anywhere . and this glomus cell is going to say , hey , wait a second . our co2 levels are starting to rise . there are high co2 levels . and again , that 's going to make the cell unhappy , and it 's going to send out more neurotransmitter , and it 's going to , of course , send out more action potentials . so two different reasons why you might get action potentials coming out of this glomus cell . and now i want to remind you that there 's this little formula . there 's this formula where carbon dioxide binds with water , and it forms h2co3 . and that 's going to break down into bicarbonate and a proton . so this is our formula . so if co2 levels are rising , like the example i just offered , then the proton level must be high as well . so a high proton concentration -- i 'm going to put it in brackets , to indicate concentration . or another way of saying that would be a low ph . so these are the things that are going to make our glomus cell send off more action potentials . so if you 're like me , you 're thinking , well , wait a second . this is really interesting . our cell is depolarizing . it can depolarize . it also has this neurotransmitter that i mentioned . our glomus cell , then , right here in blue , is basically sounding a little bit like it has properties of a nerve cell . this is a nerve cell . and the reason for that is that , if you actually take a look , these two cells have a common ancestor cell . and so in development , when the fetus is developing , there is a type of tissue called the neuroectoderm . and both of these cells , this nerve cell and this glomus cell , both are derived from this neuroectoderm . so it makes sense that they would have a lot of common features . so we know the glomus cell is not a neuron , but it 's going to be talking to neurons . in fact , you 're going to have many neurons working together in this area . and they 're going to join up , both in the aortic body and the carotid body . and these neurons , going back to the original picture , are going to meet up into a big nerve . and this nerve is going to be called the vagus nerve . the vagus nerve is going to be the one for our aortic body , sometimes also called cranial nerve number 10 . and up here with the carotid body , we have a nerve as well . this is another nerve . this one , we call the glossopharyngeal nerve . so these two nerves , the vagus nerve and the glossopharyngeal nerve -- this one , this glossopharyngeal nerve , by the way , is cranial nerve number 9 -- these two nerves are not part of the brain . they 're headed to the brain , right ? so these two nerves are fundamentally taking information from chemoreceptors that are outside of the brain . they 're not located in the brain , right ? they 're peripheral , and they 're taking information about chemicals and taking that information to the brain . that 's why we call them -- these blue areas , the carotid body and the aortic body -- we call them peripheral chemoreceptors .
|
and specifically they have a name . these things are called glomus cells . i had initially misstated it as a globus cell .
|
do glomus cells only detect plasma o2 or also the amount that is carried in the rbc ?
|
i 'm going to quickly sketch out the human heart . we 're also going to label some vessels coming off of it . so the big vessel , of course , is the aorta . this is the giant aortic arch . and the aortic arch has a couple of key branches that go , for example , up to the head and neck . it has other branches as well that go out to the arms . but these branches that are going up are the ones i 'm going to focus on . so out here on this right side , we have the right common carotid artery . and it 's called the common because , eventually , what 's going to happen is it 's going to bulge here , and then it 's going to split . and it 's going to split into the internal branch -- this is going inside -- and the external branch over here . so this would be called , for example , the right external carotid artery . and the same thing is happening on the other side , and we name it kind of the same way . we say , ok , there 's an internal branch and an external branch . this would be the internal , and this might be the external branch of the left common carotid artery . so i think you 're getting the idea now . these are named exactly the same way . and these are the ones we 're going to focus on . now , previously , we had talked about how , in these particular locations , in the internal side and then this bulgy side , we have what are called the carotid sinus . or sinuses , i suppose . but the carotid sinus is right there . and the sinus refers to any open area or open space . and there 's also an area over here in the aortic arch . and these two areas , they are the home for our baroreceptors . our baroreceptors are basically little nerves that are going to detect pressure . so they 're going to detect stretch , or pressure , that is in the vessels . and they 're going to give information back to the brain . and that 's going to help regulate our blood pressure . now , in this video , we 're actually going to focus on chemoreceptors . chemoreceptors are also important in giving us information , but they 're going to give us information about things like oxygen levels , carbon dioxide levels , ph of the blood , things like that . so these chemoreceptors -- and this gets confusing -- they 're located in a similar region , but not exactly the same region . i 'm actually going to shade in where our chemoreceptors might be , and then also you might get some over here . so these three areas are where chemoreceptors are . and they 're very , of course , closely related to where the baroreceptors are , but they 're actually in slightly different locations . and we call them the aortic body and the carotid body . and the reason we use the term `` body '' is that it 's a body of tissue . so that 's why that word gets used . and this is actually -- you can see now a slightly different location , and certainly a different job . so let me blow up some of these regions and show you , close up , what this might look like . so let me draw for you the carotid body on this side , and on the other side , we 'll do the aortic body . and i 'm basically just zooming in on it , so you can see up close what this might look like , so you can visualize it . so for the carotid body , you might have the external artery , the internal artery . and coming off of the external artery , you might have little branches , little branches serving this tissue that 's in the middle . and these branches , of course , are going to branch some more . and you 're going to get all the way down to the capillary level . and once you have little capillaries in here , there 's going to be a bunch of little cells . and these cells are , of course , going to get the nutrition from the capillary . and taken together , all these cells -- if you zoom out of this picture , this would be a little body of cells or body of tissue . and that 's why we call this the carotid body . and really , the same thing is going on on the aorta side . so on the aorta side , you 've got little branches coming off of the aorta , of course . and these branches are going to branch again , and again , and again , and again . and eventually , you 're going to get lots and lots of little capillaries . and these capillaries are going to serve all these little blue cells that i 'm drawing here , and these are the chemoreceptors that we 're talking about . so these blue cells together make up a body of tissue , and that 's where we get the term `` aortic body '' and `` carotid body . '' now , on the carotid side , one interesting fact is that this body of tissue gets a lot of blood flow , in fact , some of the highest blood flow in the entire human body . it 's about 2 liters per minute for 100 grams . and just to put that in perspective for the carotid body , imagine that you have a little 2-liter bottle of soda . i was thinking of something that would be about 2 liters , and soda came to mind . and you can imagine pouring this soda out over something that 's about 100 grams -- maybe a tomato . that 's about a 100-gram tomato . and if you could do this in one minute , if you could pour out this bottle in one minute , imagine how wet this tomato 's going to get , how much profusion , in a sense , this tomato is going to get . that is how much profusion your carotid body gets . so it really puts it in perspective how much blood flow 's going into that area . so let 's now zoom in a little bit further . let 's say i have a capillary . and inside my capillary , i 've got a little red blood cell here , floating around . and my red blood cell , of course , has some hemoglobin in it , which is a protein . and this protein has got some oxygen bound to it . i 'm going to draw little blue oxygen molecules . and of course , there 's some oxygen out here in the plasma itself as well . and if we 're in our carotid body or aortic body , you might have these special little blue cells that i 've been drawing , our peripheral chemoreceptor cells . and specifically they have a name . these things are called glomus cells . i had initially misstated it as a globus cell . but actually it 's an m -- glomus . and these oxygen molecules -- these are oxygen molecules over here -- are going to diffuse down into the tissue and get into our glomus cell . it 's going to look something like that . and if you have a lot of oxygen in the blood , of course , a lot of molecules are going to diffuse in . but if you do n't have too much in here , then not too much is going to make its way into the cell . and that 's actually the key point . because what our cell is going to be able to do is start to detect low oxygen levels . low oxygen levels in the glomus cell tells this cell that , actually , there are probably low levels in the blood . and when the levels are low , this cell is going to depolarize . its membrane is going to depolarize . and what it has on the other side are little vesicles that are full of neurotransmitter . and so when these vesicles detect that , hey , there 's a depolarization going on , these vesicles are going to dump their neurotransmitter out . and what you have waiting for them is this nice little neuron . so there 's a nice little neuron waiting patiently for a signal , and that signal is going to come in the form of a neurotransmitter . so this is how the communication works . there 's going to be a depolarization , the vessels release their neurotransmitter , and that is going to send an action potential down to our neuron . and if the oxygen levels fall really low , let 's say they get dangerously low , where the cell is very unhappy , then you 're going to get much more neurotransmitter getting dumped out , and you 're going to get many more action potentials . so this is how the glomus cell helps to detect oxygen . and in fact , it also detects carbon dioxide . because , remember , this cell is going to be making carbon dioxide . let 's say this is a little molecule of co2 , and that co2 is going to diffuse out and into the blood . well , let 's say that the blood has a lot of carbon dioxide already . let 's say that it 's loaded with carbon dioxide , lots and lots of it . in this situation , it 's going to be very difficult for carbon dioxide to make its way from the glomus cell all the way out into the plasma . and as a result , carbon dioxide starts building up . the tissue starts gathering more and more co2 , because it ca n't go anywhere . and this glomus cell is going to say , hey , wait a second . our co2 levels are starting to rise . there are high co2 levels . and again , that 's going to make the cell unhappy , and it 's going to send out more neurotransmitter , and it 's going to , of course , send out more action potentials . so two different reasons why you might get action potentials coming out of this glomus cell . and now i want to remind you that there 's this little formula . there 's this formula where carbon dioxide binds with water , and it forms h2co3 . and that 's going to break down into bicarbonate and a proton . so this is our formula . so if co2 levels are rising , like the example i just offered , then the proton level must be high as well . so a high proton concentration -- i 'm going to put it in brackets , to indicate concentration . or another way of saying that would be a low ph . so these are the things that are going to make our glomus cell send off more action potentials . so if you 're like me , you 're thinking , well , wait a second . this is really interesting . our cell is depolarizing . it can depolarize . it also has this neurotransmitter that i mentioned . our glomus cell , then , right here in blue , is basically sounding a little bit like it has properties of a nerve cell . this is a nerve cell . and the reason for that is that , if you actually take a look , these two cells have a common ancestor cell . and so in development , when the fetus is developing , there is a type of tissue called the neuroectoderm . and both of these cells , this nerve cell and this glomus cell , both are derived from this neuroectoderm . so it makes sense that they would have a lot of common features . so we know the glomus cell is not a neuron , but it 's going to be talking to neurons . in fact , you 're going to have many neurons working together in this area . and they 're going to join up , both in the aortic body and the carotid body . and these neurons , going back to the original picture , are going to meet up into a big nerve . and this nerve is going to be called the vagus nerve . the vagus nerve is going to be the one for our aortic body , sometimes also called cranial nerve number 10 . and up here with the carotid body , we have a nerve as well . this is another nerve . this one , we call the glossopharyngeal nerve . so these two nerves , the vagus nerve and the glossopharyngeal nerve -- this one , this glossopharyngeal nerve , by the way , is cranial nerve number 9 -- these two nerves are not part of the brain . they 're headed to the brain , right ? so these two nerves are fundamentally taking information from chemoreceptors that are outside of the brain . they 're not located in the brain , right ? they 're peripheral , and they 're taking information about chemicals and taking that information to the brain . that 's why we call them -- these blue areas , the carotid body and the aortic body -- we call them peripheral chemoreceptors .
|
and that 's going to help regulate our blood pressure . now , in this video , we 're actually going to focus on chemoreceptors . chemoreceptors are also important in giving us information , but they 're going to give us information about things like oxygen levels , carbon dioxide levels , ph of the blood , things like that .
|
do you have a video explaining clearly then what happens during the hypoxic drive of a patient with copd ?
|
i 'm going to quickly sketch out the human heart . we 're also going to label some vessels coming off of it . so the big vessel , of course , is the aorta . this is the giant aortic arch . and the aortic arch has a couple of key branches that go , for example , up to the head and neck . it has other branches as well that go out to the arms . but these branches that are going up are the ones i 'm going to focus on . so out here on this right side , we have the right common carotid artery . and it 's called the common because , eventually , what 's going to happen is it 's going to bulge here , and then it 's going to split . and it 's going to split into the internal branch -- this is going inside -- and the external branch over here . so this would be called , for example , the right external carotid artery . and the same thing is happening on the other side , and we name it kind of the same way . we say , ok , there 's an internal branch and an external branch . this would be the internal , and this might be the external branch of the left common carotid artery . so i think you 're getting the idea now . these are named exactly the same way . and these are the ones we 're going to focus on . now , previously , we had talked about how , in these particular locations , in the internal side and then this bulgy side , we have what are called the carotid sinus . or sinuses , i suppose . but the carotid sinus is right there . and the sinus refers to any open area or open space . and there 's also an area over here in the aortic arch . and these two areas , they are the home for our baroreceptors . our baroreceptors are basically little nerves that are going to detect pressure . so they 're going to detect stretch , or pressure , that is in the vessels . and they 're going to give information back to the brain . and that 's going to help regulate our blood pressure . now , in this video , we 're actually going to focus on chemoreceptors . chemoreceptors are also important in giving us information , but they 're going to give us information about things like oxygen levels , carbon dioxide levels , ph of the blood , things like that . so these chemoreceptors -- and this gets confusing -- they 're located in a similar region , but not exactly the same region . i 'm actually going to shade in where our chemoreceptors might be , and then also you might get some over here . so these three areas are where chemoreceptors are . and they 're very , of course , closely related to where the baroreceptors are , but they 're actually in slightly different locations . and we call them the aortic body and the carotid body . and the reason we use the term `` body '' is that it 's a body of tissue . so that 's why that word gets used . and this is actually -- you can see now a slightly different location , and certainly a different job . so let me blow up some of these regions and show you , close up , what this might look like . so let me draw for you the carotid body on this side , and on the other side , we 'll do the aortic body . and i 'm basically just zooming in on it , so you can see up close what this might look like , so you can visualize it . so for the carotid body , you might have the external artery , the internal artery . and coming off of the external artery , you might have little branches , little branches serving this tissue that 's in the middle . and these branches , of course , are going to branch some more . and you 're going to get all the way down to the capillary level . and once you have little capillaries in here , there 's going to be a bunch of little cells . and these cells are , of course , going to get the nutrition from the capillary . and taken together , all these cells -- if you zoom out of this picture , this would be a little body of cells or body of tissue . and that 's why we call this the carotid body . and really , the same thing is going on on the aorta side . so on the aorta side , you 've got little branches coming off of the aorta , of course . and these branches are going to branch again , and again , and again , and again . and eventually , you 're going to get lots and lots of little capillaries . and these capillaries are going to serve all these little blue cells that i 'm drawing here , and these are the chemoreceptors that we 're talking about . so these blue cells together make up a body of tissue , and that 's where we get the term `` aortic body '' and `` carotid body . '' now , on the carotid side , one interesting fact is that this body of tissue gets a lot of blood flow , in fact , some of the highest blood flow in the entire human body . it 's about 2 liters per minute for 100 grams . and just to put that in perspective for the carotid body , imagine that you have a little 2-liter bottle of soda . i was thinking of something that would be about 2 liters , and soda came to mind . and you can imagine pouring this soda out over something that 's about 100 grams -- maybe a tomato . that 's about a 100-gram tomato . and if you could do this in one minute , if you could pour out this bottle in one minute , imagine how wet this tomato 's going to get , how much profusion , in a sense , this tomato is going to get . that is how much profusion your carotid body gets . so it really puts it in perspective how much blood flow 's going into that area . so let 's now zoom in a little bit further . let 's say i have a capillary . and inside my capillary , i 've got a little red blood cell here , floating around . and my red blood cell , of course , has some hemoglobin in it , which is a protein . and this protein has got some oxygen bound to it . i 'm going to draw little blue oxygen molecules . and of course , there 's some oxygen out here in the plasma itself as well . and if we 're in our carotid body or aortic body , you might have these special little blue cells that i 've been drawing , our peripheral chemoreceptor cells . and specifically they have a name . these things are called glomus cells . i had initially misstated it as a globus cell . but actually it 's an m -- glomus . and these oxygen molecules -- these are oxygen molecules over here -- are going to diffuse down into the tissue and get into our glomus cell . it 's going to look something like that . and if you have a lot of oxygen in the blood , of course , a lot of molecules are going to diffuse in . but if you do n't have too much in here , then not too much is going to make its way into the cell . and that 's actually the key point . because what our cell is going to be able to do is start to detect low oxygen levels . low oxygen levels in the glomus cell tells this cell that , actually , there are probably low levels in the blood . and when the levels are low , this cell is going to depolarize . its membrane is going to depolarize . and what it has on the other side are little vesicles that are full of neurotransmitter . and so when these vesicles detect that , hey , there 's a depolarization going on , these vesicles are going to dump their neurotransmitter out . and what you have waiting for them is this nice little neuron . so there 's a nice little neuron waiting patiently for a signal , and that signal is going to come in the form of a neurotransmitter . so this is how the communication works . there 's going to be a depolarization , the vessels release their neurotransmitter , and that is going to send an action potential down to our neuron . and if the oxygen levels fall really low , let 's say they get dangerously low , where the cell is very unhappy , then you 're going to get much more neurotransmitter getting dumped out , and you 're going to get many more action potentials . so this is how the glomus cell helps to detect oxygen . and in fact , it also detects carbon dioxide . because , remember , this cell is going to be making carbon dioxide . let 's say this is a little molecule of co2 , and that co2 is going to diffuse out and into the blood . well , let 's say that the blood has a lot of carbon dioxide already . let 's say that it 's loaded with carbon dioxide , lots and lots of it . in this situation , it 's going to be very difficult for carbon dioxide to make its way from the glomus cell all the way out into the plasma . and as a result , carbon dioxide starts building up . the tissue starts gathering more and more co2 , because it ca n't go anywhere . and this glomus cell is going to say , hey , wait a second . our co2 levels are starting to rise . there are high co2 levels . and again , that 's going to make the cell unhappy , and it 's going to send out more neurotransmitter , and it 's going to , of course , send out more action potentials . so two different reasons why you might get action potentials coming out of this glomus cell . and now i want to remind you that there 's this little formula . there 's this formula where carbon dioxide binds with water , and it forms h2co3 . and that 's going to break down into bicarbonate and a proton . so this is our formula . so if co2 levels are rising , like the example i just offered , then the proton level must be high as well . so a high proton concentration -- i 'm going to put it in brackets , to indicate concentration . or another way of saying that would be a low ph . so these are the things that are going to make our glomus cell send off more action potentials . so if you 're like me , you 're thinking , well , wait a second . this is really interesting . our cell is depolarizing . it can depolarize . it also has this neurotransmitter that i mentioned . our glomus cell , then , right here in blue , is basically sounding a little bit like it has properties of a nerve cell . this is a nerve cell . and the reason for that is that , if you actually take a look , these two cells have a common ancestor cell . and so in development , when the fetus is developing , there is a type of tissue called the neuroectoderm . and both of these cells , this nerve cell and this glomus cell , both are derived from this neuroectoderm . so it makes sense that they would have a lot of common features . so we know the glomus cell is not a neuron , but it 's going to be talking to neurons . in fact , you 're going to have many neurons working together in this area . and they 're going to join up , both in the aortic body and the carotid body . and these neurons , going back to the original picture , are going to meet up into a big nerve . and this nerve is going to be called the vagus nerve . the vagus nerve is going to be the one for our aortic body , sometimes also called cranial nerve number 10 . and up here with the carotid body , we have a nerve as well . this is another nerve . this one , we call the glossopharyngeal nerve . so these two nerves , the vagus nerve and the glossopharyngeal nerve -- this one , this glossopharyngeal nerve , by the way , is cranial nerve number 9 -- these two nerves are not part of the brain . they 're headed to the brain , right ? so these two nerves are fundamentally taking information from chemoreceptors that are outside of the brain . they 're not located in the brain , right ? they 're peripheral , and they 're taking information about chemicals and taking that information to the brain . that 's why we call them -- these blue areas , the carotid body and the aortic body -- we call them peripheral chemoreceptors .
|
and as a result , carbon dioxide starts building up . the tissue starts gathering more and more co2 , because it ca n't go anywhere . and this glomus cell is going to say , hey , wait a second .
|
at 8 ; 10 , i ca n't understand how high pco2 & low po2 cause the same thing ?
|
i 'm going to quickly sketch out the human heart . we 're also going to label some vessels coming off of it . so the big vessel , of course , is the aorta . this is the giant aortic arch . and the aortic arch has a couple of key branches that go , for example , up to the head and neck . it has other branches as well that go out to the arms . but these branches that are going up are the ones i 'm going to focus on . so out here on this right side , we have the right common carotid artery . and it 's called the common because , eventually , what 's going to happen is it 's going to bulge here , and then it 's going to split . and it 's going to split into the internal branch -- this is going inside -- and the external branch over here . so this would be called , for example , the right external carotid artery . and the same thing is happening on the other side , and we name it kind of the same way . we say , ok , there 's an internal branch and an external branch . this would be the internal , and this might be the external branch of the left common carotid artery . so i think you 're getting the idea now . these are named exactly the same way . and these are the ones we 're going to focus on . now , previously , we had talked about how , in these particular locations , in the internal side and then this bulgy side , we have what are called the carotid sinus . or sinuses , i suppose . but the carotid sinus is right there . and the sinus refers to any open area or open space . and there 's also an area over here in the aortic arch . and these two areas , they are the home for our baroreceptors . our baroreceptors are basically little nerves that are going to detect pressure . so they 're going to detect stretch , or pressure , that is in the vessels . and they 're going to give information back to the brain . and that 's going to help regulate our blood pressure . now , in this video , we 're actually going to focus on chemoreceptors . chemoreceptors are also important in giving us information , but they 're going to give us information about things like oxygen levels , carbon dioxide levels , ph of the blood , things like that . so these chemoreceptors -- and this gets confusing -- they 're located in a similar region , but not exactly the same region . i 'm actually going to shade in where our chemoreceptors might be , and then also you might get some over here . so these three areas are where chemoreceptors are . and they 're very , of course , closely related to where the baroreceptors are , but they 're actually in slightly different locations . and we call them the aortic body and the carotid body . and the reason we use the term `` body '' is that it 's a body of tissue . so that 's why that word gets used . and this is actually -- you can see now a slightly different location , and certainly a different job . so let me blow up some of these regions and show you , close up , what this might look like . so let me draw for you the carotid body on this side , and on the other side , we 'll do the aortic body . and i 'm basically just zooming in on it , so you can see up close what this might look like , so you can visualize it . so for the carotid body , you might have the external artery , the internal artery . and coming off of the external artery , you might have little branches , little branches serving this tissue that 's in the middle . and these branches , of course , are going to branch some more . and you 're going to get all the way down to the capillary level . and once you have little capillaries in here , there 's going to be a bunch of little cells . and these cells are , of course , going to get the nutrition from the capillary . and taken together , all these cells -- if you zoom out of this picture , this would be a little body of cells or body of tissue . and that 's why we call this the carotid body . and really , the same thing is going on on the aorta side . so on the aorta side , you 've got little branches coming off of the aorta , of course . and these branches are going to branch again , and again , and again , and again . and eventually , you 're going to get lots and lots of little capillaries . and these capillaries are going to serve all these little blue cells that i 'm drawing here , and these are the chemoreceptors that we 're talking about . so these blue cells together make up a body of tissue , and that 's where we get the term `` aortic body '' and `` carotid body . '' now , on the carotid side , one interesting fact is that this body of tissue gets a lot of blood flow , in fact , some of the highest blood flow in the entire human body . it 's about 2 liters per minute for 100 grams . and just to put that in perspective for the carotid body , imagine that you have a little 2-liter bottle of soda . i was thinking of something that would be about 2 liters , and soda came to mind . and you can imagine pouring this soda out over something that 's about 100 grams -- maybe a tomato . that 's about a 100-gram tomato . and if you could do this in one minute , if you could pour out this bottle in one minute , imagine how wet this tomato 's going to get , how much profusion , in a sense , this tomato is going to get . that is how much profusion your carotid body gets . so it really puts it in perspective how much blood flow 's going into that area . so let 's now zoom in a little bit further . let 's say i have a capillary . and inside my capillary , i 've got a little red blood cell here , floating around . and my red blood cell , of course , has some hemoglobin in it , which is a protein . and this protein has got some oxygen bound to it . i 'm going to draw little blue oxygen molecules . and of course , there 's some oxygen out here in the plasma itself as well . and if we 're in our carotid body or aortic body , you might have these special little blue cells that i 've been drawing , our peripheral chemoreceptor cells . and specifically they have a name . these things are called glomus cells . i had initially misstated it as a globus cell . but actually it 's an m -- glomus . and these oxygen molecules -- these are oxygen molecules over here -- are going to diffuse down into the tissue and get into our glomus cell . it 's going to look something like that . and if you have a lot of oxygen in the blood , of course , a lot of molecules are going to diffuse in . but if you do n't have too much in here , then not too much is going to make its way into the cell . and that 's actually the key point . because what our cell is going to be able to do is start to detect low oxygen levels . low oxygen levels in the glomus cell tells this cell that , actually , there are probably low levels in the blood . and when the levels are low , this cell is going to depolarize . its membrane is going to depolarize . and what it has on the other side are little vesicles that are full of neurotransmitter . and so when these vesicles detect that , hey , there 's a depolarization going on , these vesicles are going to dump their neurotransmitter out . and what you have waiting for them is this nice little neuron . so there 's a nice little neuron waiting patiently for a signal , and that signal is going to come in the form of a neurotransmitter . so this is how the communication works . there 's going to be a depolarization , the vessels release their neurotransmitter , and that is going to send an action potential down to our neuron . and if the oxygen levels fall really low , let 's say they get dangerously low , where the cell is very unhappy , then you 're going to get much more neurotransmitter getting dumped out , and you 're going to get many more action potentials . so this is how the glomus cell helps to detect oxygen . and in fact , it also detects carbon dioxide . because , remember , this cell is going to be making carbon dioxide . let 's say this is a little molecule of co2 , and that co2 is going to diffuse out and into the blood . well , let 's say that the blood has a lot of carbon dioxide already . let 's say that it 's loaded with carbon dioxide , lots and lots of it . in this situation , it 's going to be very difficult for carbon dioxide to make its way from the glomus cell all the way out into the plasma . and as a result , carbon dioxide starts building up . the tissue starts gathering more and more co2 , because it ca n't go anywhere . and this glomus cell is going to say , hey , wait a second . our co2 levels are starting to rise . there are high co2 levels . and again , that 's going to make the cell unhappy , and it 's going to send out more neurotransmitter , and it 's going to , of course , send out more action potentials . so two different reasons why you might get action potentials coming out of this glomus cell . and now i want to remind you that there 's this little formula . there 's this formula where carbon dioxide binds with water , and it forms h2co3 . and that 's going to break down into bicarbonate and a proton . so this is our formula . so if co2 levels are rising , like the example i just offered , then the proton level must be high as well . so a high proton concentration -- i 'm going to put it in brackets , to indicate concentration . or another way of saying that would be a low ph . so these are the things that are going to make our glomus cell send off more action potentials . so if you 're like me , you 're thinking , well , wait a second . this is really interesting . our cell is depolarizing . it can depolarize . it also has this neurotransmitter that i mentioned . our glomus cell , then , right here in blue , is basically sounding a little bit like it has properties of a nerve cell . this is a nerve cell . and the reason for that is that , if you actually take a look , these two cells have a common ancestor cell . and so in development , when the fetus is developing , there is a type of tissue called the neuroectoderm . and both of these cells , this nerve cell and this glomus cell , both are derived from this neuroectoderm . so it makes sense that they would have a lot of common features . so we know the glomus cell is not a neuron , but it 's going to be talking to neurons . in fact , you 're going to have many neurons working together in this area . and they 're going to join up , both in the aortic body and the carotid body . and these neurons , going back to the original picture , are going to meet up into a big nerve . and this nerve is going to be called the vagus nerve . the vagus nerve is going to be the one for our aortic body , sometimes also called cranial nerve number 10 . and up here with the carotid body , we have a nerve as well . this is another nerve . this one , we call the glossopharyngeal nerve . so these two nerves , the vagus nerve and the glossopharyngeal nerve -- this one , this glossopharyngeal nerve , by the way , is cranial nerve number 9 -- these two nerves are not part of the brain . they 're headed to the brain , right ? so these two nerves are fundamentally taking information from chemoreceptors that are outside of the brain . they 're not located in the brain , right ? they 're peripheral , and they 're taking information about chemicals and taking that information to the brain . that 's why we call them -- these blue areas , the carotid body and the aortic body -- we call them peripheral chemoreceptors .
|
and if the oxygen levels fall really low , let 's say they get dangerously low , where the cell is very unhappy , then you 're going to get much more neurotransmitter getting dumped out , and you 're going to get many more action potentials . so this is how the glomus cell helps to detect oxygen . and in fact , it also detects carbon dioxide .
|
what neurotransmiter does the glomus cell secrete ?
|
i 'm going to quickly sketch out the human heart . we 're also going to label some vessels coming off of it . so the big vessel , of course , is the aorta . this is the giant aortic arch . and the aortic arch has a couple of key branches that go , for example , up to the head and neck . it has other branches as well that go out to the arms . but these branches that are going up are the ones i 'm going to focus on . so out here on this right side , we have the right common carotid artery . and it 's called the common because , eventually , what 's going to happen is it 's going to bulge here , and then it 's going to split . and it 's going to split into the internal branch -- this is going inside -- and the external branch over here . so this would be called , for example , the right external carotid artery . and the same thing is happening on the other side , and we name it kind of the same way . we say , ok , there 's an internal branch and an external branch . this would be the internal , and this might be the external branch of the left common carotid artery . so i think you 're getting the idea now . these are named exactly the same way . and these are the ones we 're going to focus on . now , previously , we had talked about how , in these particular locations , in the internal side and then this bulgy side , we have what are called the carotid sinus . or sinuses , i suppose . but the carotid sinus is right there . and the sinus refers to any open area or open space . and there 's also an area over here in the aortic arch . and these two areas , they are the home for our baroreceptors . our baroreceptors are basically little nerves that are going to detect pressure . so they 're going to detect stretch , or pressure , that is in the vessels . and they 're going to give information back to the brain . and that 's going to help regulate our blood pressure . now , in this video , we 're actually going to focus on chemoreceptors . chemoreceptors are also important in giving us information , but they 're going to give us information about things like oxygen levels , carbon dioxide levels , ph of the blood , things like that . so these chemoreceptors -- and this gets confusing -- they 're located in a similar region , but not exactly the same region . i 'm actually going to shade in where our chemoreceptors might be , and then also you might get some over here . so these three areas are where chemoreceptors are . and they 're very , of course , closely related to where the baroreceptors are , but they 're actually in slightly different locations . and we call them the aortic body and the carotid body . and the reason we use the term `` body '' is that it 's a body of tissue . so that 's why that word gets used . and this is actually -- you can see now a slightly different location , and certainly a different job . so let me blow up some of these regions and show you , close up , what this might look like . so let me draw for you the carotid body on this side , and on the other side , we 'll do the aortic body . and i 'm basically just zooming in on it , so you can see up close what this might look like , so you can visualize it . so for the carotid body , you might have the external artery , the internal artery . and coming off of the external artery , you might have little branches , little branches serving this tissue that 's in the middle . and these branches , of course , are going to branch some more . and you 're going to get all the way down to the capillary level . and once you have little capillaries in here , there 's going to be a bunch of little cells . and these cells are , of course , going to get the nutrition from the capillary . and taken together , all these cells -- if you zoom out of this picture , this would be a little body of cells or body of tissue . and that 's why we call this the carotid body . and really , the same thing is going on on the aorta side . so on the aorta side , you 've got little branches coming off of the aorta , of course . and these branches are going to branch again , and again , and again , and again . and eventually , you 're going to get lots and lots of little capillaries . and these capillaries are going to serve all these little blue cells that i 'm drawing here , and these are the chemoreceptors that we 're talking about . so these blue cells together make up a body of tissue , and that 's where we get the term `` aortic body '' and `` carotid body . '' now , on the carotid side , one interesting fact is that this body of tissue gets a lot of blood flow , in fact , some of the highest blood flow in the entire human body . it 's about 2 liters per minute for 100 grams . and just to put that in perspective for the carotid body , imagine that you have a little 2-liter bottle of soda . i was thinking of something that would be about 2 liters , and soda came to mind . and you can imagine pouring this soda out over something that 's about 100 grams -- maybe a tomato . that 's about a 100-gram tomato . and if you could do this in one minute , if you could pour out this bottle in one minute , imagine how wet this tomato 's going to get , how much profusion , in a sense , this tomato is going to get . that is how much profusion your carotid body gets . so it really puts it in perspective how much blood flow 's going into that area . so let 's now zoom in a little bit further . let 's say i have a capillary . and inside my capillary , i 've got a little red blood cell here , floating around . and my red blood cell , of course , has some hemoglobin in it , which is a protein . and this protein has got some oxygen bound to it . i 'm going to draw little blue oxygen molecules . and of course , there 's some oxygen out here in the plasma itself as well . and if we 're in our carotid body or aortic body , you might have these special little blue cells that i 've been drawing , our peripheral chemoreceptor cells . and specifically they have a name . these things are called glomus cells . i had initially misstated it as a globus cell . but actually it 's an m -- glomus . and these oxygen molecules -- these are oxygen molecules over here -- are going to diffuse down into the tissue and get into our glomus cell . it 's going to look something like that . and if you have a lot of oxygen in the blood , of course , a lot of molecules are going to diffuse in . but if you do n't have too much in here , then not too much is going to make its way into the cell . and that 's actually the key point . because what our cell is going to be able to do is start to detect low oxygen levels . low oxygen levels in the glomus cell tells this cell that , actually , there are probably low levels in the blood . and when the levels are low , this cell is going to depolarize . its membrane is going to depolarize . and what it has on the other side are little vesicles that are full of neurotransmitter . and so when these vesicles detect that , hey , there 's a depolarization going on , these vesicles are going to dump their neurotransmitter out . and what you have waiting for them is this nice little neuron . so there 's a nice little neuron waiting patiently for a signal , and that signal is going to come in the form of a neurotransmitter . so this is how the communication works . there 's going to be a depolarization , the vessels release their neurotransmitter , and that is going to send an action potential down to our neuron . and if the oxygen levels fall really low , let 's say they get dangerously low , where the cell is very unhappy , then you 're going to get much more neurotransmitter getting dumped out , and you 're going to get many more action potentials . so this is how the glomus cell helps to detect oxygen . and in fact , it also detects carbon dioxide . because , remember , this cell is going to be making carbon dioxide . let 's say this is a little molecule of co2 , and that co2 is going to diffuse out and into the blood . well , let 's say that the blood has a lot of carbon dioxide already . let 's say that it 's loaded with carbon dioxide , lots and lots of it . in this situation , it 's going to be very difficult for carbon dioxide to make its way from the glomus cell all the way out into the plasma . and as a result , carbon dioxide starts building up . the tissue starts gathering more and more co2 , because it ca n't go anywhere . and this glomus cell is going to say , hey , wait a second . our co2 levels are starting to rise . there are high co2 levels . and again , that 's going to make the cell unhappy , and it 's going to send out more neurotransmitter , and it 's going to , of course , send out more action potentials . so two different reasons why you might get action potentials coming out of this glomus cell . and now i want to remind you that there 's this little formula . there 's this formula where carbon dioxide binds with water , and it forms h2co3 . and that 's going to break down into bicarbonate and a proton . so this is our formula . so if co2 levels are rising , like the example i just offered , then the proton level must be high as well . so a high proton concentration -- i 'm going to put it in brackets , to indicate concentration . or another way of saying that would be a low ph . so these are the things that are going to make our glomus cell send off more action potentials . so if you 're like me , you 're thinking , well , wait a second . this is really interesting . our cell is depolarizing . it can depolarize . it also has this neurotransmitter that i mentioned . our glomus cell , then , right here in blue , is basically sounding a little bit like it has properties of a nerve cell . this is a nerve cell . and the reason for that is that , if you actually take a look , these two cells have a common ancestor cell . and so in development , when the fetus is developing , there is a type of tissue called the neuroectoderm . and both of these cells , this nerve cell and this glomus cell , both are derived from this neuroectoderm . so it makes sense that they would have a lot of common features . so we know the glomus cell is not a neuron , but it 's going to be talking to neurons . in fact , you 're going to have many neurons working together in this area . and they 're going to join up , both in the aortic body and the carotid body . and these neurons , going back to the original picture , are going to meet up into a big nerve . and this nerve is going to be called the vagus nerve . the vagus nerve is going to be the one for our aortic body , sometimes also called cranial nerve number 10 . and up here with the carotid body , we have a nerve as well . this is another nerve . this one , we call the glossopharyngeal nerve . so these two nerves , the vagus nerve and the glossopharyngeal nerve -- this one , this glossopharyngeal nerve , by the way , is cranial nerve number 9 -- these two nerves are not part of the brain . they 're headed to the brain , right ? so these two nerves are fundamentally taking information from chemoreceptors that are outside of the brain . they 're not located in the brain , right ? they 're peripheral , and they 're taking information about chemicals and taking that information to the brain . that 's why we call them -- these blue areas , the carotid body and the aortic body -- we call them peripheral chemoreceptors .
|
and really , the same thing is going on on the aorta side . so on the aorta side , you 've got little branches coming off of the aorta , of course . and these branches are going to branch again , and again , and again , and again .
|
baroreceptors , i 've been taught that they are located in internal carotis , not only in the aorta arch ?
|
i 'm going to quickly sketch out the human heart . we 're also going to label some vessels coming off of it . so the big vessel , of course , is the aorta . this is the giant aortic arch . and the aortic arch has a couple of key branches that go , for example , up to the head and neck . it has other branches as well that go out to the arms . but these branches that are going up are the ones i 'm going to focus on . so out here on this right side , we have the right common carotid artery . and it 's called the common because , eventually , what 's going to happen is it 's going to bulge here , and then it 's going to split . and it 's going to split into the internal branch -- this is going inside -- and the external branch over here . so this would be called , for example , the right external carotid artery . and the same thing is happening on the other side , and we name it kind of the same way . we say , ok , there 's an internal branch and an external branch . this would be the internal , and this might be the external branch of the left common carotid artery . so i think you 're getting the idea now . these are named exactly the same way . and these are the ones we 're going to focus on . now , previously , we had talked about how , in these particular locations , in the internal side and then this bulgy side , we have what are called the carotid sinus . or sinuses , i suppose . but the carotid sinus is right there . and the sinus refers to any open area or open space . and there 's also an area over here in the aortic arch . and these two areas , they are the home for our baroreceptors . our baroreceptors are basically little nerves that are going to detect pressure . so they 're going to detect stretch , or pressure , that is in the vessels . and they 're going to give information back to the brain . and that 's going to help regulate our blood pressure . now , in this video , we 're actually going to focus on chemoreceptors . chemoreceptors are also important in giving us information , but they 're going to give us information about things like oxygen levels , carbon dioxide levels , ph of the blood , things like that . so these chemoreceptors -- and this gets confusing -- they 're located in a similar region , but not exactly the same region . i 'm actually going to shade in where our chemoreceptors might be , and then also you might get some over here . so these three areas are where chemoreceptors are . and they 're very , of course , closely related to where the baroreceptors are , but they 're actually in slightly different locations . and we call them the aortic body and the carotid body . and the reason we use the term `` body '' is that it 's a body of tissue . so that 's why that word gets used . and this is actually -- you can see now a slightly different location , and certainly a different job . so let me blow up some of these regions and show you , close up , what this might look like . so let me draw for you the carotid body on this side , and on the other side , we 'll do the aortic body . and i 'm basically just zooming in on it , so you can see up close what this might look like , so you can visualize it . so for the carotid body , you might have the external artery , the internal artery . and coming off of the external artery , you might have little branches , little branches serving this tissue that 's in the middle . and these branches , of course , are going to branch some more . and you 're going to get all the way down to the capillary level . and once you have little capillaries in here , there 's going to be a bunch of little cells . and these cells are , of course , going to get the nutrition from the capillary . and taken together , all these cells -- if you zoom out of this picture , this would be a little body of cells or body of tissue . and that 's why we call this the carotid body . and really , the same thing is going on on the aorta side . so on the aorta side , you 've got little branches coming off of the aorta , of course . and these branches are going to branch again , and again , and again , and again . and eventually , you 're going to get lots and lots of little capillaries . and these capillaries are going to serve all these little blue cells that i 'm drawing here , and these are the chemoreceptors that we 're talking about . so these blue cells together make up a body of tissue , and that 's where we get the term `` aortic body '' and `` carotid body . '' now , on the carotid side , one interesting fact is that this body of tissue gets a lot of blood flow , in fact , some of the highest blood flow in the entire human body . it 's about 2 liters per minute for 100 grams . and just to put that in perspective for the carotid body , imagine that you have a little 2-liter bottle of soda . i was thinking of something that would be about 2 liters , and soda came to mind . and you can imagine pouring this soda out over something that 's about 100 grams -- maybe a tomato . that 's about a 100-gram tomato . and if you could do this in one minute , if you could pour out this bottle in one minute , imagine how wet this tomato 's going to get , how much profusion , in a sense , this tomato is going to get . that is how much profusion your carotid body gets . so it really puts it in perspective how much blood flow 's going into that area . so let 's now zoom in a little bit further . let 's say i have a capillary . and inside my capillary , i 've got a little red blood cell here , floating around . and my red blood cell , of course , has some hemoglobin in it , which is a protein . and this protein has got some oxygen bound to it . i 'm going to draw little blue oxygen molecules . and of course , there 's some oxygen out here in the plasma itself as well . and if we 're in our carotid body or aortic body , you might have these special little blue cells that i 've been drawing , our peripheral chemoreceptor cells . and specifically they have a name . these things are called glomus cells . i had initially misstated it as a globus cell . but actually it 's an m -- glomus . and these oxygen molecules -- these are oxygen molecules over here -- are going to diffuse down into the tissue and get into our glomus cell . it 's going to look something like that . and if you have a lot of oxygen in the blood , of course , a lot of molecules are going to diffuse in . but if you do n't have too much in here , then not too much is going to make its way into the cell . and that 's actually the key point . because what our cell is going to be able to do is start to detect low oxygen levels . low oxygen levels in the glomus cell tells this cell that , actually , there are probably low levels in the blood . and when the levels are low , this cell is going to depolarize . its membrane is going to depolarize . and what it has on the other side are little vesicles that are full of neurotransmitter . and so when these vesicles detect that , hey , there 's a depolarization going on , these vesicles are going to dump their neurotransmitter out . and what you have waiting for them is this nice little neuron . so there 's a nice little neuron waiting patiently for a signal , and that signal is going to come in the form of a neurotransmitter . so this is how the communication works . there 's going to be a depolarization , the vessels release their neurotransmitter , and that is going to send an action potential down to our neuron . and if the oxygen levels fall really low , let 's say they get dangerously low , where the cell is very unhappy , then you 're going to get much more neurotransmitter getting dumped out , and you 're going to get many more action potentials . so this is how the glomus cell helps to detect oxygen . and in fact , it also detects carbon dioxide . because , remember , this cell is going to be making carbon dioxide . let 's say this is a little molecule of co2 , and that co2 is going to diffuse out and into the blood . well , let 's say that the blood has a lot of carbon dioxide already . let 's say that it 's loaded with carbon dioxide , lots and lots of it . in this situation , it 's going to be very difficult for carbon dioxide to make its way from the glomus cell all the way out into the plasma . and as a result , carbon dioxide starts building up . the tissue starts gathering more and more co2 , because it ca n't go anywhere . and this glomus cell is going to say , hey , wait a second . our co2 levels are starting to rise . there are high co2 levels . and again , that 's going to make the cell unhappy , and it 's going to send out more neurotransmitter , and it 's going to , of course , send out more action potentials . so two different reasons why you might get action potentials coming out of this glomus cell . and now i want to remind you that there 's this little formula . there 's this formula where carbon dioxide binds with water , and it forms h2co3 . and that 's going to break down into bicarbonate and a proton . so this is our formula . so if co2 levels are rising , like the example i just offered , then the proton level must be high as well . so a high proton concentration -- i 'm going to put it in brackets , to indicate concentration . or another way of saying that would be a low ph . so these are the things that are going to make our glomus cell send off more action potentials . so if you 're like me , you 're thinking , well , wait a second . this is really interesting . our cell is depolarizing . it can depolarize . it also has this neurotransmitter that i mentioned . our glomus cell , then , right here in blue , is basically sounding a little bit like it has properties of a nerve cell . this is a nerve cell . and the reason for that is that , if you actually take a look , these two cells have a common ancestor cell . and so in development , when the fetus is developing , there is a type of tissue called the neuroectoderm . and both of these cells , this nerve cell and this glomus cell , both are derived from this neuroectoderm . so it makes sense that they would have a lot of common features . so we know the glomus cell is not a neuron , but it 's going to be talking to neurons . in fact , you 're going to have many neurons working together in this area . and they 're going to join up , both in the aortic body and the carotid body . and these neurons , going back to the original picture , are going to meet up into a big nerve . and this nerve is going to be called the vagus nerve . the vagus nerve is going to be the one for our aortic body , sometimes also called cranial nerve number 10 . and up here with the carotid body , we have a nerve as well . this is another nerve . this one , we call the glossopharyngeal nerve . so these two nerves , the vagus nerve and the glossopharyngeal nerve -- this one , this glossopharyngeal nerve , by the way , is cranial nerve number 9 -- these two nerves are not part of the brain . they 're headed to the brain , right ? so these two nerves are fundamentally taking information from chemoreceptors that are outside of the brain . they 're not located in the brain , right ? they 're peripheral , and they 're taking information about chemicals and taking that information to the brain . that 's why we call them -- these blue areas , the carotid body and the aortic body -- we call them peripheral chemoreceptors .
|
so a high proton concentration -- i 'm going to put it in brackets , to indicate concentration . or another way of saying that would be a low ph . so these are the things that are going to make our glomus cell send off more action potentials .
|
why does many protons make for a low ph ?
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects . each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for . so this is the number of trees initially . so he starts off with t trees , but then they tell us that he has to cut down 5 trees to control the insects . so how many trees would he have after that ? well , he started with t , and he had to cut down 5 , so he 's going to have t minus 5 trees now . now , they tell us that each of the remaining trees -- and we know there are t minus 5 remaining trees -- produced 210 oranges . so each of these t minus 5 trees are going to produce 210 oranges . so this is the number of oranges that t minus 5 trees are going to produce . this is the number of trees times the oranges per tree . so this is the total number of oranges produced after cutting the 5 trees . and then they tell us that this ends up being a total harvest of 41,790 . so this is equal to 41,790 . so we 've set up our equation . now we just have to solve for t , the number of trees that macdonald initially had . so the first thing i would do here is , well , i 'm multiplying this expression by 210 . well , why do n't i just divide both sides of this by 210 ? there 's many ways that you could do this . you could distribute the 210 and go in another direction . actually , i will do it both ways just to show that you could do it both ways . so the first way , i 'm going to divide both sides by 210 . the left-hand side simplifies to t minus 5 . the right-hand side -- let 's see , what is 4,000 -- i 'm going to do some long division here . i 'll do it on the side , so 41,790 divided by 210 . let 's see , 210 does not go into 4 . it does not going into 41 . it goes into 417 one time , because two times would be 420 -- one time . 1 times 210 is 210 . you subtract . you get 207 , and then you bring down the 9 . how many times does 210 go into 2,079 ? it looks like it would go into it not quite 10 times . it looks like it would go into it nine times . 9 times 210 is going to be -- let 's see . 9 times 0 is 0 . 9 times 1 is 9 . 9 times 2 is 18 . and then we subtract again . 9 minus 0 is 9 . we have to regroup from the thousands place , so let 's take 1,000 from there . let 's give that 1,000 to the hundreds place , so it becomes 10 hundreds . but then we have to take 100 from the hundreds place , so this becomes 9 , and give to the tens place . so this becomes 17 tens , or 170 . so 17 minus 9 is 8 . 9 minus 8 is 1 . so we get 189 . and now we can bring down another 0 . it 's a little off-center right now . and we already see that 210 goes into 1,890 nine times . 9 times 210 is 1,890 . when we subtract , we have no remainder . so what we get on the right-hand side is 199 . and now we just have to add 5 to both sides . remember , whatever we have to do to one side , we have to do the other . otherwise , the equality would n't be equal anymore . they were equal before adding 5 , so if you want them to still be equal , you have to do the same thing to both sides . so the left-hand side becomes t. i 'll do the t in that purple color . and the right-hand side becomes 204 . so he started off with 204 trees . now , i told you there 's multiple ways to do this . instead of dividing both sides by 210 , you could have decided to distribute the 210 . and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space . 5 times 210 is 1,050 -- minus 1,050 is equal to 41,790 . and then you could add 1,050 to both sides . and so let me do that , 1,050 to both sides . 1,050 , not 150 . the left-hand side , you 're just going to be left with 210t . while the right-hand side , let 's see , you 're going to be 0 plus 0 is 0 . 9 plus 5 is 14 . 1 plus 7 is 8 -- 42,840 . and now you can divide both sides by 210 . now we know where this is going to go . i could do the long division again . t is going to be equal to 42,840 divided 210 , which is equal to 204 .
|
now we know where this is going to go . i could do the long division again . t is going to be equal to 42,840 divided 210 , which is equal to 204 .
|
how does sal do that complex division using mental math ?
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects . each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for . so this is the number of trees initially . so he starts off with t trees , but then they tell us that he has to cut down 5 trees to control the insects . so how many trees would he have after that ? well , he started with t , and he had to cut down 5 , so he 's going to have t minus 5 trees now . now , they tell us that each of the remaining trees -- and we know there are t minus 5 remaining trees -- produced 210 oranges . so each of these t minus 5 trees are going to produce 210 oranges . so this is the number of oranges that t minus 5 trees are going to produce . this is the number of trees times the oranges per tree . so this is the total number of oranges produced after cutting the 5 trees . and then they tell us that this ends up being a total harvest of 41,790 . so this is equal to 41,790 . so we 've set up our equation . now we just have to solve for t , the number of trees that macdonald initially had . so the first thing i would do here is , well , i 'm multiplying this expression by 210 . well , why do n't i just divide both sides of this by 210 ? there 's many ways that you could do this . you could distribute the 210 and go in another direction . actually , i will do it both ways just to show that you could do it both ways . so the first way , i 'm going to divide both sides by 210 . the left-hand side simplifies to t minus 5 . the right-hand side -- let 's see , what is 4,000 -- i 'm going to do some long division here . i 'll do it on the side , so 41,790 divided by 210 . let 's see , 210 does not go into 4 . it does not going into 41 . it goes into 417 one time , because two times would be 420 -- one time . 1 times 210 is 210 . you subtract . you get 207 , and then you bring down the 9 . how many times does 210 go into 2,079 ? it looks like it would go into it not quite 10 times . it looks like it would go into it nine times . 9 times 210 is going to be -- let 's see . 9 times 0 is 0 . 9 times 1 is 9 . 9 times 2 is 18 . and then we subtract again . 9 minus 0 is 9 . we have to regroup from the thousands place , so let 's take 1,000 from there . let 's give that 1,000 to the hundreds place , so it becomes 10 hundreds . but then we have to take 100 from the hundreds place , so this becomes 9 , and give to the tens place . so this becomes 17 tens , or 170 . so 17 minus 9 is 8 . 9 minus 8 is 1 . so we get 189 . and now we can bring down another 0 . it 's a little off-center right now . and we already see that 210 goes into 1,890 nine times . 9 times 210 is 1,890 . when we subtract , we have no remainder . so what we get on the right-hand side is 199 . and now we just have to add 5 to both sides . remember , whatever we have to do to one side , we have to do the other . otherwise , the equality would n't be equal anymore . they were equal before adding 5 , so if you want them to still be equal , you have to do the same thing to both sides . so the left-hand side becomes t. i 'll do the t in that purple color . and the right-hand side becomes 204 . so he started off with 204 trees . now , i told you there 's multiple ways to do this . instead of dividing both sides by 210 , you could have decided to distribute the 210 . and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space . 5 times 210 is 1,050 -- minus 1,050 is equal to 41,790 . and then you could add 1,050 to both sides . and so let me do that , 1,050 to both sides . 1,050 , not 150 . the left-hand side , you 're just going to be left with 210t . while the right-hand side , let 's see , you 're going to be 0 plus 0 is 0 . 9 plus 5 is 14 . 1 plus 7 is 8 -- 42,840 . and now you can divide both sides by 210 . now we know where this is going to go . i could do the long division again . t is going to be equal to 42,840 divided 210 , which is equal to 204 .
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects .
|
if a house 's property taxes are 3 % , what is the distance of that house from the school ?
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects . each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for . so this is the number of trees initially . so he starts off with t trees , but then they tell us that he has to cut down 5 trees to control the insects . so how many trees would he have after that ? well , he started with t , and he had to cut down 5 , so he 's going to have t minus 5 trees now . now , they tell us that each of the remaining trees -- and we know there are t minus 5 remaining trees -- produced 210 oranges . so each of these t minus 5 trees are going to produce 210 oranges . so this is the number of oranges that t minus 5 trees are going to produce . this is the number of trees times the oranges per tree . so this is the total number of oranges produced after cutting the 5 trees . and then they tell us that this ends up being a total harvest of 41,790 . so this is equal to 41,790 . so we 've set up our equation . now we just have to solve for t , the number of trees that macdonald initially had . so the first thing i would do here is , well , i 'm multiplying this expression by 210 . well , why do n't i just divide both sides of this by 210 ? there 's many ways that you could do this . you could distribute the 210 and go in another direction . actually , i will do it both ways just to show that you could do it both ways . so the first way , i 'm going to divide both sides by 210 . the left-hand side simplifies to t minus 5 . the right-hand side -- let 's see , what is 4,000 -- i 'm going to do some long division here . i 'll do it on the side , so 41,790 divided by 210 . let 's see , 210 does not go into 4 . it does not going into 41 . it goes into 417 one time , because two times would be 420 -- one time . 1 times 210 is 210 . you subtract . you get 207 , and then you bring down the 9 . how many times does 210 go into 2,079 ? it looks like it would go into it not quite 10 times . it looks like it would go into it nine times . 9 times 210 is going to be -- let 's see . 9 times 0 is 0 . 9 times 1 is 9 . 9 times 2 is 18 . and then we subtract again . 9 minus 0 is 9 . we have to regroup from the thousands place , so let 's take 1,000 from there . let 's give that 1,000 to the hundreds place , so it becomes 10 hundreds . but then we have to take 100 from the hundreds place , so this becomes 9 , and give to the tens place . so this becomes 17 tens , or 170 . so 17 minus 9 is 8 . 9 minus 8 is 1 . so we get 189 . and now we can bring down another 0 . it 's a little off-center right now . and we already see that 210 goes into 1,890 nine times . 9 times 210 is 1,890 . when we subtract , we have no remainder . so what we get on the right-hand side is 199 . and now we just have to add 5 to both sides . remember , whatever we have to do to one side , we have to do the other . otherwise , the equality would n't be equal anymore . they were equal before adding 5 , so if you want them to still be equal , you have to do the same thing to both sides . so the left-hand side becomes t. i 'll do the t in that purple color . and the right-hand side becomes 204 . so he started off with 204 trees . now , i told you there 's multiple ways to do this . instead of dividing both sides by 210 , you could have decided to distribute the 210 . and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space . 5 times 210 is 1,050 -- minus 1,050 is equal to 41,790 . and then you could add 1,050 to both sides . and so let me do that , 1,050 to both sides . 1,050 , not 150 . the left-hand side , you 're just going to be left with 210t . while the right-hand side , let 's see , you 're going to be 0 plus 0 is 0 . 9 plus 5 is 14 . 1 plus 7 is 8 -- 42,840 . and now you can divide both sides by 210 . now we know where this is going to go . i could do the long division again . t is going to be equal to 42,840 divided 210 , which is equal to 204 .
|
and now you can divide both sides by 210 . now we know where this is going to go . i could do the long division again .
|
so in a different context of a question how do we know we are supposed to use parenthesis ?
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects . each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for . so this is the number of trees initially . so he starts off with t trees , but then they tell us that he has to cut down 5 trees to control the insects . so how many trees would he have after that ? well , he started with t , and he had to cut down 5 , so he 's going to have t minus 5 trees now . now , they tell us that each of the remaining trees -- and we know there are t minus 5 remaining trees -- produced 210 oranges . so each of these t minus 5 trees are going to produce 210 oranges . so this is the number of oranges that t minus 5 trees are going to produce . this is the number of trees times the oranges per tree . so this is the total number of oranges produced after cutting the 5 trees . and then they tell us that this ends up being a total harvest of 41,790 . so this is equal to 41,790 . so we 've set up our equation . now we just have to solve for t , the number of trees that macdonald initially had . so the first thing i would do here is , well , i 'm multiplying this expression by 210 . well , why do n't i just divide both sides of this by 210 ? there 's many ways that you could do this . you could distribute the 210 and go in another direction . actually , i will do it both ways just to show that you could do it both ways . so the first way , i 'm going to divide both sides by 210 . the left-hand side simplifies to t minus 5 . the right-hand side -- let 's see , what is 4,000 -- i 'm going to do some long division here . i 'll do it on the side , so 41,790 divided by 210 . let 's see , 210 does not go into 4 . it does not going into 41 . it goes into 417 one time , because two times would be 420 -- one time . 1 times 210 is 210 . you subtract . you get 207 , and then you bring down the 9 . how many times does 210 go into 2,079 ? it looks like it would go into it not quite 10 times . it looks like it would go into it nine times . 9 times 210 is going to be -- let 's see . 9 times 0 is 0 . 9 times 1 is 9 . 9 times 2 is 18 . and then we subtract again . 9 minus 0 is 9 . we have to regroup from the thousands place , so let 's take 1,000 from there . let 's give that 1,000 to the hundreds place , so it becomes 10 hundreds . but then we have to take 100 from the hundreds place , so this becomes 9 , and give to the tens place . so this becomes 17 tens , or 170 . so 17 minus 9 is 8 . 9 minus 8 is 1 . so we get 189 . and now we can bring down another 0 . it 's a little off-center right now . and we already see that 210 goes into 1,890 nine times . 9 times 210 is 1,890 . when we subtract , we have no remainder . so what we get on the right-hand side is 199 . and now we just have to add 5 to both sides . remember , whatever we have to do to one side , we have to do the other . otherwise , the equality would n't be equal anymore . they were equal before adding 5 , so if you want them to still be equal , you have to do the same thing to both sides . so the left-hand side becomes t. i 'll do the t in that purple color . and the right-hand side becomes 204 . so he started off with 204 trees . now , i told you there 's multiple ways to do this . instead of dividing both sides by 210 , you could have decided to distribute the 210 . and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space . 5 times 210 is 1,050 -- minus 1,050 is equal to 41,790 . and then you could add 1,050 to both sides . and so let me do that , 1,050 to both sides . 1,050 , not 150 . the left-hand side , you 're just going to be left with 210t . while the right-hand side , let 's see , you 're going to be 0 plus 0 is 0 . 9 plus 5 is 14 . 1 plus 7 is 8 -- 42,840 . and now you can divide both sides by 210 . now we know where this is going to go . i could do the long division again . t is going to be equal to 42,840 divided 210 , which is equal to 204 .
|
each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for .
|
the problem asks how many trees did mcdonald initially start with ... should n't the answer be 204 + 5 = 209 ?
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects . each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for . so this is the number of trees initially . so he starts off with t trees , but then they tell us that he has to cut down 5 trees to control the insects . so how many trees would he have after that ? well , he started with t , and he had to cut down 5 , so he 's going to have t minus 5 trees now . now , they tell us that each of the remaining trees -- and we know there are t minus 5 remaining trees -- produced 210 oranges . so each of these t minus 5 trees are going to produce 210 oranges . so this is the number of oranges that t minus 5 trees are going to produce . this is the number of trees times the oranges per tree . so this is the total number of oranges produced after cutting the 5 trees . and then they tell us that this ends up being a total harvest of 41,790 . so this is equal to 41,790 . so we 've set up our equation . now we just have to solve for t , the number of trees that macdonald initially had . so the first thing i would do here is , well , i 'm multiplying this expression by 210 . well , why do n't i just divide both sides of this by 210 ? there 's many ways that you could do this . you could distribute the 210 and go in another direction . actually , i will do it both ways just to show that you could do it both ways . so the first way , i 'm going to divide both sides by 210 . the left-hand side simplifies to t minus 5 . the right-hand side -- let 's see , what is 4,000 -- i 'm going to do some long division here . i 'll do it on the side , so 41,790 divided by 210 . let 's see , 210 does not go into 4 . it does not going into 41 . it goes into 417 one time , because two times would be 420 -- one time . 1 times 210 is 210 . you subtract . you get 207 , and then you bring down the 9 . how many times does 210 go into 2,079 ? it looks like it would go into it not quite 10 times . it looks like it would go into it nine times . 9 times 210 is going to be -- let 's see . 9 times 0 is 0 . 9 times 1 is 9 . 9 times 2 is 18 . and then we subtract again . 9 minus 0 is 9 . we have to regroup from the thousands place , so let 's take 1,000 from there . let 's give that 1,000 to the hundreds place , so it becomes 10 hundreds . but then we have to take 100 from the hundreds place , so this becomes 9 , and give to the tens place . so this becomes 17 tens , or 170 . so 17 minus 9 is 8 . 9 minus 8 is 1 . so we get 189 . and now we can bring down another 0 . it 's a little off-center right now . and we already see that 210 goes into 1,890 nine times . 9 times 210 is 1,890 . when we subtract , we have no remainder . so what we get on the right-hand side is 199 . and now we just have to add 5 to both sides . remember , whatever we have to do to one side , we have to do the other . otherwise , the equality would n't be equal anymore . they were equal before adding 5 , so if you want them to still be equal , you have to do the same thing to both sides . so the left-hand side becomes t. i 'll do the t in that purple color . and the right-hand side becomes 204 . so he started off with 204 trees . now , i told you there 's multiple ways to do this . instead of dividing both sides by 210 , you could have decided to distribute the 210 . and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space . 5 times 210 is 1,050 -- minus 1,050 is equal to 41,790 . and then you could add 1,050 to both sides . and so let me do that , 1,050 to both sides . 1,050 , not 150 . the left-hand side , you 're just going to be left with 210t . while the right-hand side , let 's see , you 're going to be 0 plus 0 is 0 . 9 plus 5 is 14 . 1 plus 7 is 8 -- 42,840 . and now you can divide both sides by 210 . now we know where this is going to go . i could do the long division again . t is going to be equal to 42,840 divided 210 , which is equal to 204 .
|
so this is equal to 41,790 . so we 've set up our equation . now we just have to solve for t , the number of trees that macdonald initially had .
|
is there some sort of pattern that you can use when comes to different variations of the same linear equation problems ?
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects . each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for . so this is the number of trees initially . so he starts off with t trees , but then they tell us that he has to cut down 5 trees to control the insects . so how many trees would he have after that ? well , he started with t , and he had to cut down 5 , so he 's going to have t minus 5 trees now . now , they tell us that each of the remaining trees -- and we know there are t minus 5 remaining trees -- produced 210 oranges . so each of these t minus 5 trees are going to produce 210 oranges . so this is the number of oranges that t minus 5 trees are going to produce . this is the number of trees times the oranges per tree . so this is the total number of oranges produced after cutting the 5 trees . and then they tell us that this ends up being a total harvest of 41,790 . so this is equal to 41,790 . so we 've set up our equation . now we just have to solve for t , the number of trees that macdonald initially had . so the first thing i would do here is , well , i 'm multiplying this expression by 210 . well , why do n't i just divide both sides of this by 210 ? there 's many ways that you could do this . you could distribute the 210 and go in another direction . actually , i will do it both ways just to show that you could do it both ways . so the first way , i 'm going to divide both sides by 210 . the left-hand side simplifies to t minus 5 . the right-hand side -- let 's see , what is 4,000 -- i 'm going to do some long division here . i 'll do it on the side , so 41,790 divided by 210 . let 's see , 210 does not go into 4 . it does not going into 41 . it goes into 417 one time , because two times would be 420 -- one time . 1 times 210 is 210 . you subtract . you get 207 , and then you bring down the 9 . how many times does 210 go into 2,079 ? it looks like it would go into it not quite 10 times . it looks like it would go into it nine times . 9 times 210 is going to be -- let 's see . 9 times 0 is 0 . 9 times 1 is 9 . 9 times 2 is 18 . and then we subtract again . 9 minus 0 is 9 . we have to regroup from the thousands place , so let 's take 1,000 from there . let 's give that 1,000 to the hundreds place , so it becomes 10 hundreds . but then we have to take 100 from the hundreds place , so this becomes 9 , and give to the tens place . so this becomes 17 tens , or 170 . so 17 minus 9 is 8 . 9 minus 8 is 1 . so we get 189 . and now we can bring down another 0 . it 's a little off-center right now . and we already see that 210 goes into 1,890 nine times . 9 times 210 is 1,890 . when we subtract , we have no remainder . so what we get on the right-hand side is 199 . and now we just have to add 5 to both sides . remember , whatever we have to do to one side , we have to do the other . otherwise , the equality would n't be equal anymore . they were equal before adding 5 , so if you want them to still be equal , you have to do the same thing to both sides . so the left-hand side becomes t. i 'll do the t in that purple color . and the right-hand side becomes 204 . so he started off with 204 trees . now , i told you there 's multiple ways to do this . instead of dividing both sides by 210 , you could have decided to distribute the 210 . and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space . 5 times 210 is 1,050 -- minus 1,050 is equal to 41,790 . and then you could add 1,050 to both sides . and so let me do that , 1,050 to both sides . 1,050 , not 150 . the left-hand side , you 're just going to be left with 210t . while the right-hand side , let 's see , you 're going to be 0 plus 0 is 0 . 9 plus 5 is 14 . 1 plus 7 is 8 -- 42,840 . and now you can divide both sides by 210 . now we know where this is going to go . i could do the long division again . t is going to be equal to 42,840 divided 210 , which is equal to 204 .
|
9 times 1 is 9 . 9 times 2 is 18 . and then we subtract again .
|
determine whether the ordered pairs given are solutions of the following linear inequality in two ( 5,2 ) ( 4 , 2 ) x+4y < 4 yes or no is the ordered pair 5 , 2 a solution of the linear inequality ?
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects . each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for . so this is the number of trees initially . so he starts off with t trees , but then they tell us that he has to cut down 5 trees to control the insects . so how many trees would he have after that ? well , he started with t , and he had to cut down 5 , so he 's going to have t minus 5 trees now . now , they tell us that each of the remaining trees -- and we know there are t minus 5 remaining trees -- produced 210 oranges . so each of these t minus 5 trees are going to produce 210 oranges . so this is the number of oranges that t minus 5 trees are going to produce . this is the number of trees times the oranges per tree . so this is the total number of oranges produced after cutting the 5 trees . and then they tell us that this ends up being a total harvest of 41,790 . so this is equal to 41,790 . so we 've set up our equation . now we just have to solve for t , the number of trees that macdonald initially had . so the first thing i would do here is , well , i 'm multiplying this expression by 210 . well , why do n't i just divide both sides of this by 210 ? there 's many ways that you could do this . you could distribute the 210 and go in another direction . actually , i will do it both ways just to show that you could do it both ways . so the first way , i 'm going to divide both sides by 210 . the left-hand side simplifies to t minus 5 . the right-hand side -- let 's see , what is 4,000 -- i 'm going to do some long division here . i 'll do it on the side , so 41,790 divided by 210 . let 's see , 210 does not go into 4 . it does not going into 41 . it goes into 417 one time , because two times would be 420 -- one time . 1 times 210 is 210 . you subtract . you get 207 , and then you bring down the 9 . how many times does 210 go into 2,079 ? it looks like it would go into it not quite 10 times . it looks like it would go into it nine times . 9 times 210 is going to be -- let 's see . 9 times 0 is 0 . 9 times 1 is 9 . 9 times 2 is 18 . and then we subtract again . 9 minus 0 is 9 . we have to regroup from the thousands place , so let 's take 1,000 from there . let 's give that 1,000 to the hundreds place , so it becomes 10 hundreds . but then we have to take 100 from the hundreds place , so this becomes 9 , and give to the tens place . so this becomes 17 tens , or 170 . so 17 minus 9 is 8 . 9 minus 8 is 1 . so we get 189 . and now we can bring down another 0 . it 's a little off-center right now . and we already see that 210 goes into 1,890 nine times . 9 times 210 is 1,890 . when we subtract , we have no remainder . so what we get on the right-hand side is 199 . and now we just have to add 5 to both sides . remember , whatever we have to do to one side , we have to do the other . otherwise , the equality would n't be equal anymore . they were equal before adding 5 , so if you want them to still be equal , you have to do the same thing to both sides . so the left-hand side becomes t. i 'll do the t in that purple color . and the right-hand side becomes 204 . so he started off with 204 trees . now , i told you there 's multiple ways to do this . instead of dividing both sides by 210 , you could have decided to distribute the 210 . and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space . 5 times 210 is 1,050 -- minus 1,050 is equal to 41,790 . and then you could add 1,050 to both sides . and so let me do that , 1,050 to both sides . 1,050 , not 150 . the left-hand side , you 're just going to be left with 210t . while the right-hand side , let 's see , you 're going to be 0 plus 0 is 0 . 9 plus 5 is 14 . 1 plus 7 is 8 -- 42,840 . and now you can divide both sides by 210 . now we know where this is going to go . i could do the long division again . t is going to be equal to 42,840 divided 210 , which is equal to 204 .
|
remember , whatever we have to do to one side , we have to do the other . otherwise , the equality would n't be equal anymore . they were equal before adding 5 , so if you want them to still be equal , you have to do the same thing to both sides .
|
how would you do this : when a number n is increased by 25 % and 11 is added , the result is 51 ?
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects . each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for . so this is the number of trees initially . so he starts off with t trees , but then they tell us that he has to cut down 5 trees to control the insects . so how many trees would he have after that ? well , he started with t , and he had to cut down 5 , so he 's going to have t minus 5 trees now . now , they tell us that each of the remaining trees -- and we know there are t minus 5 remaining trees -- produced 210 oranges . so each of these t minus 5 trees are going to produce 210 oranges . so this is the number of oranges that t minus 5 trees are going to produce . this is the number of trees times the oranges per tree . so this is the total number of oranges produced after cutting the 5 trees . and then they tell us that this ends up being a total harvest of 41,790 . so this is equal to 41,790 . so we 've set up our equation . now we just have to solve for t , the number of trees that macdonald initially had . so the first thing i would do here is , well , i 'm multiplying this expression by 210 . well , why do n't i just divide both sides of this by 210 ? there 's many ways that you could do this . you could distribute the 210 and go in another direction . actually , i will do it both ways just to show that you could do it both ways . so the first way , i 'm going to divide both sides by 210 . the left-hand side simplifies to t minus 5 . the right-hand side -- let 's see , what is 4,000 -- i 'm going to do some long division here . i 'll do it on the side , so 41,790 divided by 210 . let 's see , 210 does not go into 4 . it does not going into 41 . it goes into 417 one time , because two times would be 420 -- one time . 1 times 210 is 210 . you subtract . you get 207 , and then you bring down the 9 . how many times does 210 go into 2,079 ? it looks like it would go into it not quite 10 times . it looks like it would go into it nine times . 9 times 210 is going to be -- let 's see . 9 times 0 is 0 . 9 times 1 is 9 . 9 times 2 is 18 . and then we subtract again . 9 minus 0 is 9 . we have to regroup from the thousands place , so let 's take 1,000 from there . let 's give that 1,000 to the hundreds place , so it becomes 10 hundreds . but then we have to take 100 from the hundreds place , so this becomes 9 , and give to the tens place . so this becomes 17 tens , or 170 . so 17 minus 9 is 8 . 9 minus 8 is 1 . so we get 189 . and now we can bring down another 0 . it 's a little off-center right now . and we already see that 210 goes into 1,890 nine times . 9 times 210 is 1,890 . when we subtract , we have no remainder . so what we get on the right-hand side is 199 . and now we just have to add 5 to both sides . remember , whatever we have to do to one side , we have to do the other . otherwise , the equality would n't be equal anymore . they were equal before adding 5 , so if you want them to still be equal , you have to do the same thing to both sides . so the left-hand side becomes t. i 'll do the t in that purple color . and the right-hand side becomes 204 . so he started off with 204 trees . now , i told you there 's multiple ways to do this . instead of dividing both sides by 210 , you could have decided to distribute the 210 . and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space . 5 times 210 is 1,050 -- minus 1,050 is equal to 41,790 . and then you could add 1,050 to both sides . and so let me do that , 1,050 to both sides . 1,050 , not 150 . the left-hand side , you 're just going to be left with 210t . while the right-hand side , let 's see , you 're going to be 0 plus 0 is 0 . 9 plus 5 is 14 . 1 plus 7 is 8 -- 42,840 . and now you can divide both sides by 210 . now we know where this is going to go . i could do the long division again . t is going to be equal to 42,840 divided 210 , which is equal to 204 .
|
and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space .
|
why did n't you just take 210 away from 5 then you would of got 204 ?
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects . each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for . so this is the number of trees initially . so he starts off with t trees , but then they tell us that he has to cut down 5 trees to control the insects . so how many trees would he have after that ? well , he started with t , and he had to cut down 5 , so he 's going to have t minus 5 trees now . now , they tell us that each of the remaining trees -- and we know there are t minus 5 remaining trees -- produced 210 oranges . so each of these t minus 5 trees are going to produce 210 oranges . so this is the number of oranges that t minus 5 trees are going to produce . this is the number of trees times the oranges per tree . so this is the total number of oranges produced after cutting the 5 trees . and then they tell us that this ends up being a total harvest of 41,790 . so this is equal to 41,790 . so we 've set up our equation . now we just have to solve for t , the number of trees that macdonald initially had . so the first thing i would do here is , well , i 'm multiplying this expression by 210 . well , why do n't i just divide both sides of this by 210 ? there 's many ways that you could do this . you could distribute the 210 and go in another direction . actually , i will do it both ways just to show that you could do it both ways . so the first way , i 'm going to divide both sides by 210 . the left-hand side simplifies to t minus 5 . the right-hand side -- let 's see , what is 4,000 -- i 'm going to do some long division here . i 'll do it on the side , so 41,790 divided by 210 . let 's see , 210 does not go into 4 . it does not going into 41 . it goes into 417 one time , because two times would be 420 -- one time . 1 times 210 is 210 . you subtract . you get 207 , and then you bring down the 9 . how many times does 210 go into 2,079 ? it looks like it would go into it not quite 10 times . it looks like it would go into it nine times . 9 times 210 is going to be -- let 's see . 9 times 0 is 0 . 9 times 1 is 9 . 9 times 2 is 18 . and then we subtract again . 9 minus 0 is 9 . we have to regroup from the thousands place , so let 's take 1,000 from there . let 's give that 1,000 to the hundreds place , so it becomes 10 hundreds . but then we have to take 100 from the hundreds place , so this becomes 9 , and give to the tens place . so this becomes 17 tens , or 170 . so 17 minus 9 is 8 . 9 minus 8 is 1 . so we get 189 . and now we can bring down another 0 . it 's a little off-center right now . and we already see that 210 goes into 1,890 nine times . 9 times 210 is 1,890 . when we subtract , we have no remainder . so what we get on the right-hand side is 199 . and now we just have to add 5 to both sides . remember , whatever we have to do to one side , we have to do the other . otherwise , the equality would n't be equal anymore . they were equal before adding 5 , so if you want them to still be equal , you have to do the same thing to both sides . so the left-hand side becomes t. i 'll do the t in that purple color . and the right-hand side becomes 204 . so he started off with 204 trees . now , i told you there 's multiple ways to do this . instead of dividing both sides by 210 , you could have decided to distribute the 210 . and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space . 5 times 210 is 1,050 -- minus 1,050 is equal to 41,790 . and then you could add 1,050 to both sides . and so let me do that , 1,050 to both sides . 1,050 , not 150 . the left-hand side , you 're just going to be left with 210t . while the right-hand side , let 's see , you 're going to be 0 plus 0 is 0 . 9 plus 5 is 14 . 1 plus 7 is 8 -- 42,840 . and now you can divide both sides by 210 . now we know where this is going to go . i could do the long division again . t is going to be equal to 42,840 divided 210 , which is equal to 204 .
|
he had to cut down 5 trees to control the insects . each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ?
|
maria 20 apples and oranges.apples cost .40 $ and oranges cost .35 $ how many of each fruit did maria bought ?
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects . each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for . so this is the number of trees initially . so he starts off with t trees , but then they tell us that he has to cut down 5 trees to control the insects . so how many trees would he have after that ? well , he started with t , and he had to cut down 5 , so he 's going to have t minus 5 trees now . now , they tell us that each of the remaining trees -- and we know there are t minus 5 remaining trees -- produced 210 oranges . so each of these t minus 5 trees are going to produce 210 oranges . so this is the number of oranges that t minus 5 trees are going to produce . this is the number of trees times the oranges per tree . so this is the total number of oranges produced after cutting the 5 trees . and then they tell us that this ends up being a total harvest of 41,790 . so this is equal to 41,790 . so we 've set up our equation . now we just have to solve for t , the number of trees that macdonald initially had . so the first thing i would do here is , well , i 'm multiplying this expression by 210 . well , why do n't i just divide both sides of this by 210 ? there 's many ways that you could do this . you could distribute the 210 and go in another direction . actually , i will do it both ways just to show that you could do it both ways . so the first way , i 'm going to divide both sides by 210 . the left-hand side simplifies to t minus 5 . the right-hand side -- let 's see , what is 4,000 -- i 'm going to do some long division here . i 'll do it on the side , so 41,790 divided by 210 . let 's see , 210 does not go into 4 . it does not going into 41 . it goes into 417 one time , because two times would be 420 -- one time . 1 times 210 is 210 . you subtract . you get 207 , and then you bring down the 9 . how many times does 210 go into 2,079 ? it looks like it would go into it not quite 10 times . it looks like it would go into it nine times . 9 times 210 is going to be -- let 's see . 9 times 0 is 0 . 9 times 1 is 9 . 9 times 2 is 18 . and then we subtract again . 9 minus 0 is 9 . we have to regroup from the thousands place , so let 's take 1,000 from there . let 's give that 1,000 to the hundreds place , so it becomes 10 hundreds . but then we have to take 100 from the hundreds place , so this becomes 9 , and give to the tens place . so this becomes 17 tens , or 170 . so 17 minus 9 is 8 . 9 minus 8 is 1 . so we get 189 . and now we can bring down another 0 . it 's a little off-center right now . and we already see that 210 goes into 1,890 nine times . 9 times 210 is 1,890 . when we subtract , we have no remainder . so what we get on the right-hand side is 199 . and now we just have to add 5 to both sides . remember , whatever we have to do to one side , we have to do the other . otherwise , the equality would n't be equal anymore . they were equal before adding 5 , so if you want them to still be equal , you have to do the same thing to both sides . so the left-hand side becomes t. i 'll do the t in that purple color . and the right-hand side becomes 204 . so he started off with 204 trees . now , i told you there 's multiple ways to do this . instead of dividing both sides by 210 , you could have decided to distribute the 210 . and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space . 5 times 210 is 1,050 -- minus 1,050 is equal to 41,790 . and then you could add 1,050 to both sides . and so let me do that , 1,050 to both sides . 1,050 , not 150 . the left-hand side , you 're just going to be left with 210t . while the right-hand side , let 's see , you 're going to be 0 plus 0 is 0 . 9 plus 5 is 14 . 1 plus 7 is 8 -- 42,840 . and now you can divide both sides by 210 . now we know where this is going to go . i could do the long division again . t is going to be equal to 42,840 divided 210 , which is equal to 204 .
|
so this is equal to 41,790 . so we 've set up our equation . now we just have to solve for t , the number of trees that macdonald initially had .
|
what is the linear equation ?
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects . each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for . so this is the number of trees initially . so he starts off with t trees , but then they tell us that he has to cut down 5 trees to control the insects . so how many trees would he have after that ? well , he started with t , and he had to cut down 5 , so he 's going to have t minus 5 trees now . now , they tell us that each of the remaining trees -- and we know there are t minus 5 remaining trees -- produced 210 oranges . so each of these t minus 5 trees are going to produce 210 oranges . so this is the number of oranges that t minus 5 trees are going to produce . this is the number of trees times the oranges per tree . so this is the total number of oranges produced after cutting the 5 trees . and then they tell us that this ends up being a total harvest of 41,790 . so this is equal to 41,790 . so we 've set up our equation . now we just have to solve for t , the number of trees that macdonald initially had . so the first thing i would do here is , well , i 'm multiplying this expression by 210 . well , why do n't i just divide both sides of this by 210 ? there 's many ways that you could do this . you could distribute the 210 and go in another direction . actually , i will do it both ways just to show that you could do it both ways . so the first way , i 'm going to divide both sides by 210 . the left-hand side simplifies to t minus 5 . the right-hand side -- let 's see , what is 4,000 -- i 'm going to do some long division here . i 'll do it on the side , so 41,790 divided by 210 . let 's see , 210 does not go into 4 . it does not going into 41 . it goes into 417 one time , because two times would be 420 -- one time . 1 times 210 is 210 . you subtract . you get 207 , and then you bring down the 9 . how many times does 210 go into 2,079 ? it looks like it would go into it not quite 10 times . it looks like it would go into it nine times . 9 times 210 is going to be -- let 's see . 9 times 0 is 0 . 9 times 1 is 9 . 9 times 2 is 18 . and then we subtract again . 9 minus 0 is 9 . we have to regroup from the thousands place , so let 's take 1,000 from there . let 's give that 1,000 to the hundreds place , so it becomes 10 hundreds . but then we have to take 100 from the hundreds place , so this becomes 9 , and give to the tens place . so this becomes 17 tens , or 170 . so 17 minus 9 is 8 . 9 minus 8 is 1 . so we get 189 . and now we can bring down another 0 . it 's a little off-center right now . and we already see that 210 goes into 1,890 nine times . 9 times 210 is 1,890 . when we subtract , we have no remainder . so what we get on the right-hand side is 199 . and now we just have to add 5 to both sides . remember , whatever we have to do to one side , we have to do the other . otherwise , the equality would n't be equal anymore . they were equal before adding 5 , so if you want them to still be equal , you have to do the same thing to both sides . so the left-hand side becomes t. i 'll do the t in that purple color . and the right-hand side becomes 204 . so he started off with 204 trees . now , i told you there 's multiple ways to do this . instead of dividing both sides by 210 , you could have decided to distribute the 210 . and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space . 5 times 210 is 1,050 -- minus 1,050 is equal to 41,790 . and then you could add 1,050 to both sides . and so let me do that , 1,050 to both sides . 1,050 , not 150 . the left-hand side , you 're just going to be left with 210t . while the right-hand side , let 's see , you 're going to be 0 plus 0 is 0 . 9 plus 5 is 14 . 1 plus 7 is 8 -- 42,840 . and now you can divide both sides by 210 . now we know where this is going to go . i could do the long division again . t is going to be equal to 42,840 divided 210 , which is equal to 204 .
|
and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space .
|
9 sal says that number of trees ( t-5 ) times number of oranges per trees ( 210 ) , so when in math we divide instead of multiplying and why not it is 210/ ( t-5 ) ?
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects . each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for . so this is the number of trees initially . so he starts off with t trees , but then they tell us that he has to cut down 5 trees to control the insects . so how many trees would he have after that ? well , he started with t , and he had to cut down 5 , so he 's going to have t minus 5 trees now . now , they tell us that each of the remaining trees -- and we know there are t minus 5 remaining trees -- produced 210 oranges . so each of these t minus 5 trees are going to produce 210 oranges . so this is the number of oranges that t minus 5 trees are going to produce . this is the number of trees times the oranges per tree . so this is the total number of oranges produced after cutting the 5 trees . and then they tell us that this ends up being a total harvest of 41,790 . so this is equal to 41,790 . so we 've set up our equation . now we just have to solve for t , the number of trees that macdonald initially had . so the first thing i would do here is , well , i 'm multiplying this expression by 210 . well , why do n't i just divide both sides of this by 210 ? there 's many ways that you could do this . you could distribute the 210 and go in another direction . actually , i will do it both ways just to show that you could do it both ways . so the first way , i 'm going to divide both sides by 210 . the left-hand side simplifies to t minus 5 . the right-hand side -- let 's see , what is 4,000 -- i 'm going to do some long division here . i 'll do it on the side , so 41,790 divided by 210 . let 's see , 210 does not go into 4 . it does not going into 41 . it goes into 417 one time , because two times would be 420 -- one time . 1 times 210 is 210 . you subtract . you get 207 , and then you bring down the 9 . how many times does 210 go into 2,079 ? it looks like it would go into it not quite 10 times . it looks like it would go into it nine times . 9 times 210 is going to be -- let 's see . 9 times 0 is 0 . 9 times 1 is 9 . 9 times 2 is 18 . and then we subtract again . 9 minus 0 is 9 . we have to regroup from the thousands place , so let 's take 1,000 from there . let 's give that 1,000 to the hundreds place , so it becomes 10 hundreds . but then we have to take 100 from the hundreds place , so this becomes 9 , and give to the tens place . so this becomes 17 tens , or 170 . so 17 minus 9 is 8 . 9 minus 8 is 1 . so we get 189 . and now we can bring down another 0 . it 's a little off-center right now . and we already see that 210 goes into 1,890 nine times . 9 times 210 is 1,890 . when we subtract , we have no remainder . so what we get on the right-hand side is 199 . and now we just have to add 5 to both sides . remember , whatever we have to do to one side , we have to do the other . otherwise , the equality would n't be equal anymore . they were equal before adding 5 , so if you want them to still be equal , you have to do the same thing to both sides . so the left-hand side becomes t. i 'll do the t in that purple color . and the right-hand side becomes 204 . so he started off with 204 trees . now , i told you there 's multiple ways to do this . instead of dividing both sides by 210 , you could have decided to distribute the 210 . and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space . 5 times 210 is 1,050 -- minus 1,050 is equal to 41,790 . and then you could add 1,050 to both sides . and so let me do that , 1,050 to both sides . 1,050 , not 150 . the left-hand side , you 're just going to be left with 210t . while the right-hand side , let 's see , you 're going to be 0 plus 0 is 0 . 9 plus 5 is 14 . 1 plus 7 is 8 -- 42,840 . and now you can divide both sides by 210 . now we know where this is going to go . i could do the long division again . t is going to be equal to 42,840 divided 210 , which is equal to 204 .
|
actually , i will do it both ways just to show that you could do it both ways . so the first way , i 'm going to divide both sides by 210 . the left-hand side simplifies to t minus 5 .
|
it is able to block the sun because it is way father and the sun might be smaller than the sun , but how much light does the moon receive and how bright it is ?
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects . each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for . so this is the number of trees initially . so he starts off with t trees , but then they tell us that he has to cut down 5 trees to control the insects . so how many trees would he have after that ? well , he started with t , and he had to cut down 5 , so he 's going to have t minus 5 trees now . now , they tell us that each of the remaining trees -- and we know there are t minus 5 remaining trees -- produced 210 oranges . so each of these t minus 5 trees are going to produce 210 oranges . so this is the number of oranges that t minus 5 trees are going to produce . this is the number of trees times the oranges per tree . so this is the total number of oranges produced after cutting the 5 trees . and then they tell us that this ends up being a total harvest of 41,790 . so this is equal to 41,790 . so we 've set up our equation . now we just have to solve for t , the number of trees that macdonald initially had . so the first thing i would do here is , well , i 'm multiplying this expression by 210 . well , why do n't i just divide both sides of this by 210 ? there 's many ways that you could do this . you could distribute the 210 and go in another direction . actually , i will do it both ways just to show that you could do it both ways . so the first way , i 'm going to divide both sides by 210 . the left-hand side simplifies to t minus 5 . the right-hand side -- let 's see , what is 4,000 -- i 'm going to do some long division here . i 'll do it on the side , so 41,790 divided by 210 . let 's see , 210 does not go into 4 . it does not going into 41 . it goes into 417 one time , because two times would be 420 -- one time . 1 times 210 is 210 . you subtract . you get 207 , and then you bring down the 9 . how many times does 210 go into 2,079 ? it looks like it would go into it not quite 10 times . it looks like it would go into it nine times . 9 times 210 is going to be -- let 's see . 9 times 0 is 0 . 9 times 1 is 9 . 9 times 2 is 18 . and then we subtract again . 9 minus 0 is 9 . we have to regroup from the thousands place , so let 's take 1,000 from there . let 's give that 1,000 to the hundreds place , so it becomes 10 hundreds . but then we have to take 100 from the hundreds place , so this becomes 9 , and give to the tens place . so this becomes 17 tens , or 170 . so 17 minus 9 is 8 . 9 minus 8 is 1 . so we get 189 . and now we can bring down another 0 . it 's a little off-center right now . and we already see that 210 goes into 1,890 nine times . 9 times 210 is 1,890 . when we subtract , we have no remainder . so what we get on the right-hand side is 199 . and now we just have to add 5 to both sides . remember , whatever we have to do to one side , we have to do the other . otherwise , the equality would n't be equal anymore . they were equal before adding 5 , so if you want them to still be equal , you have to do the same thing to both sides . so the left-hand side becomes t. i 'll do the t in that purple color . and the right-hand side becomes 204 . so he started off with 204 trees . now , i told you there 's multiple ways to do this . instead of dividing both sides by 210 , you could have decided to distribute the 210 . and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space . 5 times 210 is 1,050 -- minus 1,050 is equal to 41,790 . and then you could add 1,050 to both sides . and so let me do that , 1,050 to both sides . 1,050 , not 150 . the left-hand side , you 're just going to be left with 210t . while the right-hand side , let 's see , you 're going to be 0 plus 0 is 0 . 9 plus 5 is 14 . 1 plus 7 is 8 -- 42,840 . and now you can divide both sides by 210 . now we know where this is going to go . i could do the long division again . t is going to be equal to 42,840 divided 210 , which is equal to 204 .
|
each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for .
|
now we will come up with a function telling us how many units a factory can produce depending on how many skilled workers and how many unskilled workers there are ?
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects . each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for . so this is the number of trees initially . so he starts off with t trees , but then they tell us that he has to cut down 5 trees to control the insects . so how many trees would he have after that ? well , he started with t , and he had to cut down 5 , so he 's going to have t minus 5 trees now . now , they tell us that each of the remaining trees -- and we know there are t minus 5 remaining trees -- produced 210 oranges . so each of these t minus 5 trees are going to produce 210 oranges . so this is the number of oranges that t minus 5 trees are going to produce . this is the number of trees times the oranges per tree . so this is the total number of oranges produced after cutting the 5 trees . and then they tell us that this ends up being a total harvest of 41,790 . so this is equal to 41,790 . so we 've set up our equation . now we just have to solve for t , the number of trees that macdonald initially had . so the first thing i would do here is , well , i 'm multiplying this expression by 210 . well , why do n't i just divide both sides of this by 210 ? there 's many ways that you could do this . you could distribute the 210 and go in another direction . actually , i will do it both ways just to show that you could do it both ways . so the first way , i 'm going to divide both sides by 210 . the left-hand side simplifies to t minus 5 . the right-hand side -- let 's see , what is 4,000 -- i 'm going to do some long division here . i 'll do it on the side , so 41,790 divided by 210 . let 's see , 210 does not go into 4 . it does not going into 41 . it goes into 417 one time , because two times would be 420 -- one time . 1 times 210 is 210 . you subtract . you get 207 , and then you bring down the 9 . how many times does 210 go into 2,079 ? it looks like it would go into it not quite 10 times . it looks like it would go into it nine times . 9 times 210 is going to be -- let 's see . 9 times 0 is 0 . 9 times 1 is 9 . 9 times 2 is 18 . and then we subtract again . 9 minus 0 is 9 . we have to regroup from the thousands place , so let 's take 1,000 from there . let 's give that 1,000 to the hundreds place , so it becomes 10 hundreds . but then we have to take 100 from the hundreds place , so this becomes 9 , and give to the tens place . so this becomes 17 tens , or 170 . so 17 minus 9 is 8 . 9 minus 8 is 1 . so we get 189 . and now we can bring down another 0 . it 's a little off-center right now . and we already see that 210 goes into 1,890 nine times . 9 times 210 is 1,890 . when we subtract , we have no remainder . so what we get on the right-hand side is 199 . and now we just have to add 5 to both sides . remember , whatever we have to do to one side , we have to do the other . otherwise , the equality would n't be equal anymore . they were equal before adding 5 , so if you want them to still be equal , you have to do the same thing to both sides . so the left-hand side becomes t. i 'll do the t in that purple color . and the right-hand side becomes 204 . so he started off with 204 trees . now , i told you there 's multiple ways to do this . instead of dividing both sides by 210 , you could have decided to distribute the 210 . and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space . 5 times 210 is 1,050 -- minus 1,050 is equal to 41,790 . and then you could add 1,050 to both sides . and so let me do that , 1,050 to both sides . 1,050 , not 150 . the left-hand side , you 're just going to be left with 210t . while the right-hand side , let 's see , you 're going to be 0 plus 0 is 0 . 9 plus 5 is 14 . 1 plus 7 is 8 -- 42,840 . and now you can divide both sides by 210 . now we know where this is going to go . i could do the long division again . t is going to be equal to 42,840 divided 210 , which is equal to 204 .
|
and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space .
|
i do n't understand why you put 210 outside of the ( t-5 ) ?
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects . each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for . so this is the number of trees initially . so he starts off with t trees , but then they tell us that he has to cut down 5 trees to control the insects . so how many trees would he have after that ? well , he started with t , and he had to cut down 5 , so he 's going to have t minus 5 trees now . now , they tell us that each of the remaining trees -- and we know there are t minus 5 remaining trees -- produced 210 oranges . so each of these t minus 5 trees are going to produce 210 oranges . so this is the number of oranges that t minus 5 trees are going to produce . this is the number of trees times the oranges per tree . so this is the total number of oranges produced after cutting the 5 trees . and then they tell us that this ends up being a total harvest of 41,790 . so this is equal to 41,790 . so we 've set up our equation . now we just have to solve for t , the number of trees that macdonald initially had . so the first thing i would do here is , well , i 'm multiplying this expression by 210 . well , why do n't i just divide both sides of this by 210 ? there 's many ways that you could do this . you could distribute the 210 and go in another direction . actually , i will do it both ways just to show that you could do it both ways . so the first way , i 'm going to divide both sides by 210 . the left-hand side simplifies to t minus 5 . the right-hand side -- let 's see , what is 4,000 -- i 'm going to do some long division here . i 'll do it on the side , so 41,790 divided by 210 . let 's see , 210 does not go into 4 . it does not going into 41 . it goes into 417 one time , because two times would be 420 -- one time . 1 times 210 is 210 . you subtract . you get 207 , and then you bring down the 9 . how many times does 210 go into 2,079 ? it looks like it would go into it not quite 10 times . it looks like it would go into it nine times . 9 times 210 is going to be -- let 's see . 9 times 0 is 0 . 9 times 1 is 9 . 9 times 2 is 18 . and then we subtract again . 9 minus 0 is 9 . we have to regroup from the thousands place , so let 's take 1,000 from there . let 's give that 1,000 to the hundreds place , so it becomes 10 hundreds . but then we have to take 100 from the hundreds place , so this becomes 9 , and give to the tens place . so this becomes 17 tens , or 170 . so 17 minus 9 is 8 . 9 minus 8 is 1 . so we get 189 . and now we can bring down another 0 . it 's a little off-center right now . and we already see that 210 goes into 1,890 nine times . 9 times 210 is 1,890 . when we subtract , we have no remainder . so what we get on the right-hand side is 199 . and now we just have to add 5 to both sides . remember , whatever we have to do to one side , we have to do the other . otherwise , the equality would n't be equal anymore . they were equal before adding 5 , so if you want them to still be equal , you have to do the same thing to both sides . so the left-hand side becomes t. i 'll do the t in that purple color . and the right-hand side becomes 204 . so he started off with 204 trees . now , i told you there 's multiple ways to do this . instead of dividing both sides by 210 , you could have decided to distribute the 210 . and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space . 5 times 210 is 1,050 -- minus 1,050 is equal to 41,790 . and then you could add 1,050 to both sides . and so let me do that , 1,050 to both sides . 1,050 , not 150 . the left-hand side , you 're just going to be left with 210t . while the right-hand side , let 's see , you 're going to be 0 plus 0 is 0 . 9 plus 5 is 14 . 1 plus 7 is 8 -- 42,840 . and now you can divide both sides by 210 . now we know where this is going to go . i could do the long division again . t is going to be equal to 42,840 divided 210 , which is equal to 204 .
|
it does not going into 41 . it goes into 417 one time , because two times would be 420 -- one time . 1 times 210 is 210 .
|
how do you distinguish between two in the word problem ?
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects . each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for . so this is the number of trees initially . so he starts off with t trees , but then they tell us that he has to cut down 5 trees to control the insects . so how many trees would he have after that ? well , he started with t , and he had to cut down 5 , so he 's going to have t minus 5 trees now . now , they tell us that each of the remaining trees -- and we know there are t minus 5 remaining trees -- produced 210 oranges . so each of these t minus 5 trees are going to produce 210 oranges . so this is the number of oranges that t minus 5 trees are going to produce . this is the number of trees times the oranges per tree . so this is the total number of oranges produced after cutting the 5 trees . and then they tell us that this ends up being a total harvest of 41,790 . so this is equal to 41,790 . so we 've set up our equation . now we just have to solve for t , the number of trees that macdonald initially had . so the first thing i would do here is , well , i 'm multiplying this expression by 210 . well , why do n't i just divide both sides of this by 210 ? there 's many ways that you could do this . you could distribute the 210 and go in another direction . actually , i will do it both ways just to show that you could do it both ways . so the first way , i 'm going to divide both sides by 210 . the left-hand side simplifies to t minus 5 . the right-hand side -- let 's see , what is 4,000 -- i 'm going to do some long division here . i 'll do it on the side , so 41,790 divided by 210 . let 's see , 210 does not go into 4 . it does not going into 41 . it goes into 417 one time , because two times would be 420 -- one time . 1 times 210 is 210 . you subtract . you get 207 , and then you bring down the 9 . how many times does 210 go into 2,079 ? it looks like it would go into it not quite 10 times . it looks like it would go into it nine times . 9 times 210 is going to be -- let 's see . 9 times 0 is 0 . 9 times 1 is 9 . 9 times 2 is 18 . and then we subtract again . 9 minus 0 is 9 . we have to regroup from the thousands place , so let 's take 1,000 from there . let 's give that 1,000 to the hundreds place , so it becomes 10 hundreds . but then we have to take 100 from the hundreds place , so this becomes 9 , and give to the tens place . so this becomes 17 tens , or 170 . so 17 minus 9 is 8 . 9 minus 8 is 1 . so we get 189 . and now we can bring down another 0 . it 's a little off-center right now . and we already see that 210 goes into 1,890 nine times . 9 times 210 is 1,890 . when we subtract , we have no remainder . so what we get on the right-hand side is 199 . and now we just have to add 5 to both sides . remember , whatever we have to do to one side , we have to do the other . otherwise , the equality would n't be equal anymore . they were equal before adding 5 , so if you want them to still be equal , you have to do the same thing to both sides . so the left-hand side becomes t. i 'll do the t in that purple color . and the right-hand side becomes 204 . so he started off with 204 trees . now , i told you there 's multiple ways to do this . instead of dividing both sides by 210 , you could have decided to distribute the 210 . and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space . 5 times 210 is 1,050 -- minus 1,050 is equal to 41,790 . and then you could add 1,050 to both sides . and so let me do that , 1,050 to both sides . 1,050 , not 150 . the left-hand side , you 're just going to be left with 210t . while the right-hand side , let 's see , you 're going to be 0 plus 0 is 0 . 9 plus 5 is 14 . 1 plus 7 is 8 -- 42,840 . and now you can divide both sides by 210 . now we know where this is going to go . i could do the long division again . t is going to be equal to 42,840 divided 210 , which is equal to 204 .
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects .
|
what was the maximum height , in feet , of the ball above the ground after it was kicked ?
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects . each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for . so this is the number of trees initially . so he starts off with t trees , but then they tell us that he has to cut down 5 trees to control the insects . so how many trees would he have after that ? well , he started with t , and he had to cut down 5 , so he 's going to have t minus 5 trees now . now , they tell us that each of the remaining trees -- and we know there are t minus 5 remaining trees -- produced 210 oranges . so each of these t minus 5 trees are going to produce 210 oranges . so this is the number of oranges that t minus 5 trees are going to produce . this is the number of trees times the oranges per tree . so this is the total number of oranges produced after cutting the 5 trees . and then they tell us that this ends up being a total harvest of 41,790 . so this is equal to 41,790 . so we 've set up our equation . now we just have to solve for t , the number of trees that macdonald initially had . so the first thing i would do here is , well , i 'm multiplying this expression by 210 . well , why do n't i just divide both sides of this by 210 ? there 's many ways that you could do this . you could distribute the 210 and go in another direction . actually , i will do it both ways just to show that you could do it both ways . so the first way , i 'm going to divide both sides by 210 . the left-hand side simplifies to t minus 5 . the right-hand side -- let 's see , what is 4,000 -- i 'm going to do some long division here . i 'll do it on the side , so 41,790 divided by 210 . let 's see , 210 does not go into 4 . it does not going into 41 . it goes into 417 one time , because two times would be 420 -- one time . 1 times 210 is 210 . you subtract . you get 207 , and then you bring down the 9 . how many times does 210 go into 2,079 ? it looks like it would go into it not quite 10 times . it looks like it would go into it nine times . 9 times 210 is going to be -- let 's see . 9 times 0 is 0 . 9 times 1 is 9 . 9 times 2 is 18 . and then we subtract again . 9 minus 0 is 9 . we have to regroup from the thousands place , so let 's take 1,000 from there . let 's give that 1,000 to the hundreds place , so it becomes 10 hundreds . but then we have to take 100 from the hundreds place , so this becomes 9 , and give to the tens place . so this becomes 17 tens , or 170 . so 17 minus 9 is 8 . 9 minus 8 is 1 . so we get 189 . and now we can bring down another 0 . it 's a little off-center right now . and we already see that 210 goes into 1,890 nine times . 9 times 210 is 1,890 . when we subtract , we have no remainder . so what we get on the right-hand side is 199 . and now we just have to add 5 to both sides . remember , whatever we have to do to one side , we have to do the other . otherwise , the equality would n't be equal anymore . they were equal before adding 5 , so if you want them to still be equal , you have to do the same thing to both sides . so the left-hand side becomes t. i 'll do the t in that purple color . and the right-hand side becomes 204 . so he started off with 204 trees . now , i told you there 's multiple ways to do this . instead of dividing both sides by 210 , you could have decided to distribute the 210 . and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space . 5 times 210 is 1,050 -- minus 1,050 is equal to 41,790 . and then you could add 1,050 to both sides . and so let me do that , 1,050 to both sides . 1,050 , not 150 . the left-hand side , you 're just going to be left with 210t . while the right-hand side , let 's see , you 're going to be 0 plus 0 is 0 . 9 plus 5 is 14 . 1 plus 7 is 8 -- 42,840 . and now you can divide both sides by 210 . now we know where this is going to go . i could do the long division again . t is going to be equal to 42,840 divided 210 , which is equal to 204 .
|
let 's let t equal what they 're asking is for . so this is the number of trees initially . so he starts off with t trees , but then they tell us that he has to cut down 5 trees to control the insects .
|
the product of 8 and a number increase by 6 is 104 what is the number ?
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects . each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for . so this is the number of trees initially . so he starts off with t trees , but then they tell us that he has to cut down 5 trees to control the insects . so how many trees would he have after that ? well , he started with t , and he had to cut down 5 , so he 's going to have t minus 5 trees now . now , they tell us that each of the remaining trees -- and we know there are t minus 5 remaining trees -- produced 210 oranges . so each of these t minus 5 trees are going to produce 210 oranges . so this is the number of oranges that t minus 5 trees are going to produce . this is the number of trees times the oranges per tree . so this is the total number of oranges produced after cutting the 5 trees . and then they tell us that this ends up being a total harvest of 41,790 . so this is equal to 41,790 . so we 've set up our equation . now we just have to solve for t , the number of trees that macdonald initially had . so the first thing i would do here is , well , i 'm multiplying this expression by 210 . well , why do n't i just divide both sides of this by 210 ? there 's many ways that you could do this . you could distribute the 210 and go in another direction . actually , i will do it both ways just to show that you could do it both ways . so the first way , i 'm going to divide both sides by 210 . the left-hand side simplifies to t minus 5 . the right-hand side -- let 's see , what is 4,000 -- i 'm going to do some long division here . i 'll do it on the side , so 41,790 divided by 210 . let 's see , 210 does not go into 4 . it does not going into 41 . it goes into 417 one time , because two times would be 420 -- one time . 1 times 210 is 210 . you subtract . you get 207 , and then you bring down the 9 . how many times does 210 go into 2,079 ? it looks like it would go into it not quite 10 times . it looks like it would go into it nine times . 9 times 210 is going to be -- let 's see . 9 times 0 is 0 . 9 times 1 is 9 . 9 times 2 is 18 . and then we subtract again . 9 minus 0 is 9 . we have to regroup from the thousands place , so let 's take 1,000 from there . let 's give that 1,000 to the hundreds place , so it becomes 10 hundreds . but then we have to take 100 from the hundreds place , so this becomes 9 , and give to the tens place . so this becomes 17 tens , or 170 . so 17 minus 9 is 8 . 9 minus 8 is 1 . so we get 189 . and now we can bring down another 0 . it 's a little off-center right now . and we already see that 210 goes into 1,890 nine times . 9 times 210 is 1,890 . when we subtract , we have no remainder . so what we get on the right-hand side is 199 . and now we just have to add 5 to both sides . remember , whatever we have to do to one side , we have to do the other . otherwise , the equality would n't be equal anymore . they were equal before adding 5 , so if you want them to still be equal , you have to do the same thing to both sides . so the left-hand side becomes t. i 'll do the t in that purple color . and the right-hand side becomes 204 . so he started off with 204 trees . now , i told you there 's multiple ways to do this . instead of dividing both sides by 210 , you could have decided to distribute the 210 . and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space . 5 times 210 is 1,050 -- minus 1,050 is equal to 41,790 . and then you could add 1,050 to both sides . and so let me do that , 1,050 to both sides . 1,050 , not 150 . the left-hand side , you 're just going to be left with 210t . while the right-hand side , let 's see , you 're going to be 0 plus 0 is 0 . 9 plus 5 is 14 . 1 plus 7 is 8 -- 42,840 . and now you can divide both sides by 210 . now we know where this is going to go . i could do the long division again . t is going to be equal to 42,840 divided 210 , which is equal to 204 .
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects .
|
is there something online to help people form equations from word problems ?
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects . each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for . so this is the number of trees initially . so he starts off with t trees , but then they tell us that he has to cut down 5 trees to control the insects . so how many trees would he have after that ? well , he started with t , and he had to cut down 5 , so he 's going to have t minus 5 trees now . now , they tell us that each of the remaining trees -- and we know there are t minus 5 remaining trees -- produced 210 oranges . so each of these t minus 5 trees are going to produce 210 oranges . so this is the number of oranges that t minus 5 trees are going to produce . this is the number of trees times the oranges per tree . so this is the total number of oranges produced after cutting the 5 trees . and then they tell us that this ends up being a total harvest of 41,790 . so this is equal to 41,790 . so we 've set up our equation . now we just have to solve for t , the number of trees that macdonald initially had . so the first thing i would do here is , well , i 'm multiplying this expression by 210 . well , why do n't i just divide both sides of this by 210 ? there 's many ways that you could do this . you could distribute the 210 and go in another direction . actually , i will do it both ways just to show that you could do it both ways . so the first way , i 'm going to divide both sides by 210 . the left-hand side simplifies to t minus 5 . the right-hand side -- let 's see , what is 4,000 -- i 'm going to do some long division here . i 'll do it on the side , so 41,790 divided by 210 . let 's see , 210 does not go into 4 . it does not going into 41 . it goes into 417 one time , because two times would be 420 -- one time . 1 times 210 is 210 . you subtract . you get 207 , and then you bring down the 9 . how many times does 210 go into 2,079 ? it looks like it would go into it not quite 10 times . it looks like it would go into it nine times . 9 times 210 is going to be -- let 's see . 9 times 0 is 0 . 9 times 1 is 9 . 9 times 2 is 18 . and then we subtract again . 9 minus 0 is 9 . we have to regroup from the thousands place , so let 's take 1,000 from there . let 's give that 1,000 to the hundreds place , so it becomes 10 hundreds . but then we have to take 100 from the hundreds place , so this becomes 9 , and give to the tens place . so this becomes 17 tens , or 170 . so 17 minus 9 is 8 . 9 minus 8 is 1 . so we get 189 . and now we can bring down another 0 . it 's a little off-center right now . and we already see that 210 goes into 1,890 nine times . 9 times 210 is 1,890 . when we subtract , we have no remainder . so what we get on the right-hand side is 199 . and now we just have to add 5 to both sides . remember , whatever we have to do to one side , we have to do the other . otherwise , the equality would n't be equal anymore . they were equal before adding 5 , so if you want them to still be equal , you have to do the same thing to both sides . so the left-hand side becomes t. i 'll do the t in that purple color . and the right-hand side becomes 204 . so he started off with 204 trees . now , i told you there 's multiple ways to do this . instead of dividing both sides by 210 , you could have decided to distribute the 210 . and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space . 5 times 210 is 1,050 -- minus 1,050 is equal to 41,790 . and then you could add 1,050 to both sides . and so let me do that , 1,050 to both sides . 1,050 , not 150 . the left-hand side , you 're just going to be left with 210t . while the right-hand side , let 's see , you 're going to be 0 plus 0 is 0 . 9 plus 5 is 14 . 1 plus 7 is 8 -- 42,840 . and now you can divide both sides by 210 . now we know where this is going to go . i could do the long division again . t is going to be equal to 42,840 divided 210 , which is equal to 204 .
|
now we know where this is going to go . i could do the long division again . t is going to be equal to 42,840 divided 210 , which is equal to 204 .
|
why did sal have to use his own division ?
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects . each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for . so this is the number of trees initially . so he starts off with t trees , but then they tell us that he has to cut down 5 trees to control the insects . so how many trees would he have after that ? well , he started with t , and he had to cut down 5 , so he 's going to have t minus 5 trees now . now , they tell us that each of the remaining trees -- and we know there are t minus 5 remaining trees -- produced 210 oranges . so each of these t minus 5 trees are going to produce 210 oranges . so this is the number of oranges that t minus 5 trees are going to produce . this is the number of trees times the oranges per tree . so this is the total number of oranges produced after cutting the 5 trees . and then they tell us that this ends up being a total harvest of 41,790 . so this is equal to 41,790 . so we 've set up our equation . now we just have to solve for t , the number of trees that macdonald initially had . so the first thing i would do here is , well , i 'm multiplying this expression by 210 . well , why do n't i just divide both sides of this by 210 ? there 's many ways that you could do this . you could distribute the 210 and go in another direction . actually , i will do it both ways just to show that you could do it both ways . so the first way , i 'm going to divide both sides by 210 . the left-hand side simplifies to t minus 5 . the right-hand side -- let 's see , what is 4,000 -- i 'm going to do some long division here . i 'll do it on the side , so 41,790 divided by 210 . let 's see , 210 does not go into 4 . it does not going into 41 . it goes into 417 one time , because two times would be 420 -- one time . 1 times 210 is 210 . you subtract . you get 207 , and then you bring down the 9 . how many times does 210 go into 2,079 ? it looks like it would go into it not quite 10 times . it looks like it would go into it nine times . 9 times 210 is going to be -- let 's see . 9 times 0 is 0 . 9 times 1 is 9 . 9 times 2 is 18 . and then we subtract again . 9 minus 0 is 9 . we have to regroup from the thousands place , so let 's take 1,000 from there . let 's give that 1,000 to the hundreds place , so it becomes 10 hundreds . but then we have to take 100 from the hundreds place , so this becomes 9 , and give to the tens place . so this becomes 17 tens , or 170 . so 17 minus 9 is 8 . 9 minus 8 is 1 . so we get 189 . and now we can bring down another 0 . it 's a little off-center right now . and we already see that 210 goes into 1,890 nine times . 9 times 210 is 1,890 . when we subtract , we have no remainder . so what we get on the right-hand side is 199 . and now we just have to add 5 to both sides . remember , whatever we have to do to one side , we have to do the other . otherwise , the equality would n't be equal anymore . they were equal before adding 5 , so if you want them to still be equal , you have to do the same thing to both sides . so the left-hand side becomes t. i 'll do the t in that purple color . and the right-hand side becomes 204 . so he started off with 204 trees . now , i told you there 's multiple ways to do this . instead of dividing both sides by 210 , you could have decided to distribute the 210 . and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space . 5 times 210 is 1,050 -- minus 1,050 is equal to 41,790 . and then you could add 1,050 to both sides . and so let me do that , 1,050 to both sides . 1,050 , not 150 . the left-hand side , you 're just going to be left with 210t . while the right-hand side , let 's see , you 're going to be 0 plus 0 is 0 . 9 plus 5 is 14 . 1 plus 7 is 8 -- 42,840 . and now you can divide both sides by 210 . now we know where this is going to go . i could do the long division again . t is going to be equal to 42,840 divided 210 , which is equal to 204 .
|
so the left-hand side becomes t. i 'll do the t in that purple color . and the right-hand side becomes 204 . so he started off with 204 trees .
|
the current sum of ages of anjli and aarti is 49.how old is aarti right now ?
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects . each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for . so this is the number of trees initially . so he starts off with t trees , but then they tell us that he has to cut down 5 trees to control the insects . so how many trees would he have after that ? well , he started with t , and he had to cut down 5 , so he 's going to have t minus 5 trees now . now , they tell us that each of the remaining trees -- and we know there are t minus 5 remaining trees -- produced 210 oranges . so each of these t minus 5 trees are going to produce 210 oranges . so this is the number of oranges that t minus 5 trees are going to produce . this is the number of trees times the oranges per tree . so this is the total number of oranges produced after cutting the 5 trees . and then they tell us that this ends up being a total harvest of 41,790 . so this is equal to 41,790 . so we 've set up our equation . now we just have to solve for t , the number of trees that macdonald initially had . so the first thing i would do here is , well , i 'm multiplying this expression by 210 . well , why do n't i just divide both sides of this by 210 ? there 's many ways that you could do this . you could distribute the 210 and go in another direction . actually , i will do it both ways just to show that you could do it both ways . so the first way , i 'm going to divide both sides by 210 . the left-hand side simplifies to t minus 5 . the right-hand side -- let 's see , what is 4,000 -- i 'm going to do some long division here . i 'll do it on the side , so 41,790 divided by 210 . let 's see , 210 does not go into 4 . it does not going into 41 . it goes into 417 one time , because two times would be 420 -- one time . 1 times 210 is 210 . you subtract . you get 207 , and then you bring down the 9 . how many times does 210 go into 2,079 ? it looks like it would go into it not quite 10 times . it looks like it would go into it nine times . 9 times 210 is going to be -- let 's see . 9 times 0 is 0 . 9 times 1 is 9 . 9 times 2 is 18 . and then we subtract again . 9 minus 0 is 9 . we have to regroup from the thousands place , so let 's take 1,000 from there . let 's give that 1,000 to the hundreds place , so it becomes 10 hundreds . but then we have to take 100 from the hundreds place , so this becomes 9 , and give to the tens place . so this becomes 17 tens , or 170 . so 17 minus 9 is 8 . 9 minus 8 is 1 . so we get 189 . and now we can bring down another 0 . it 's a little off-center right now . and we already see that 210 goes into 1,890 nine times . 9 times 210 is 1,890 . when we subtract , we have no remainder . so what we get on the right-hand side is 199 . and now we just have to add 5 to both sides . remember , whatever we have to do to one side , we have to do the other . otherwise , the equality would n't be equal anymore . they were equal before adding 5 , so if you want them to still be equal , you have to do the same thing to both sides . so the left-hand side becomes t. i 'll do the t in that purple color . and the right-hand side becomes 204 . so he started off with 204 trees . now , i told you there 's multiple ways to do this . instead of dividing both sides by 210 , you could have decided to distribute the 210 . and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space . 5 times 210 is 1,050 -- minus 1,050 is equal to 41,790 . and then you could add 1,050 to both sides . and so let me do that , 1,050 to both sides . 1,050 , not 150 . the left-hand side , you 're just going to be left with 210t . while the right-hand side , let 's see , you 're going to be 0 plus 0 is 0 . 9 plus 5 is 14 . 1 plus 7 is 8 -- 42,840 . and now you can divide both sides by 210 . now we know where this is going to go . i could do the long division again . t is going to be equal to 42,840 divided 210 , which is equal to 204 .
|
he had to cut down 5 trees to control the insects . each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ?
|
why did mcdonald need so many oranges ?
|
macdonald had a farm with a certain number of orange trees . he had to cut down 5 trees to control the insects . each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for . so this is the number of trees initially . so he starts off with t trees , but then they tell us that he has to cut down 5 trees to control the insects . so how many trees would he have after that ? well , he started with t , and he had to cut down 5 , so he 's going to have t minus 5 trees now . now , they tell us that each of the remaining trees -- and we know there are t minus 5 remaining trees -- produced 210 oranges . so each of these t minus 5 trees are going to produce 210 oranges . so this is the number of oranges that t minus 5 trees are going to produce . this is the number of trees times the oranges per tree . so this is the total number of oranges produced after cutting the 5 trees . and then they tell us that this ends up being a total harvest of 41,790 . so this is equal to 41,790 . so we 've set up our equation . now we just have to solve for t , the number of trees that macdonald initially had . so the first thing i would do here is , well , i 'm multiplying this expression by 210 . well , why do n't i just divide both sides of this by 210 ? there 's many ways that you could do this . you could distribute the 210 and go in another direction . actually , i will do it both ways just to show that you could do it both ways . so the first way , i 'm going to divide both sides by 210 . the left-hand side simplifies to t minus 5 . the right-hand side -- let 's see , what is 4,000 -- i 'm going to do some long division here . i 'll do it on the side , so 41,790 divided by 210 . let 's see , 210 does not go into 4 . it does not going into 41 . it goes into 417 one time , because two times would be 420 -- one time . 1 times 210 is 210 . you subtract . you get 207 , and then you bring down the 9 . how many times does 210 go into 2,079 ? it looks like it would go into it not quite 10 times . it looks like it would go into it nine times . 9 times 210 is going to be -- let 's see . 9 times 0 is 0 . 9 times 1 is 9 . 9 times 2 is 18 . and then we subtract again . 9 minus 0 is 9 . we have to regroup from the thousands place , so let 's take 1,000 from there . let 's give that 1,000 to the hundreds place , so it becomes 10 hundreds . but then we have to take 100 from the hundreds place , so this becomes 9 , and give to the tens place . so this becomes 17 tens , or 170 . so 17 minus 9 is 8 . 9 minus 8 is 1 . so we get 189 . and now we can bring down another 0 . it 's a little off-center right now . and we already see that 210 goes into 1,890 nine times . 9 times 210 is 1,890 . when we subtract , we have no remainder . so what we get on the right-hand side is 199 . and now we just have to add 5 to both sides . remember , whatever we have to do to one side , we have to do the other . otherwise , the equality would n't be equal anymore . they were equal before adding 5 , so if you want them to still be equal , you have to do the same thing to both sides . so the left-hand side becomes t. i 'll do the t in that purple color . and the right-hand side becomes 204 . so he started off with 204 trees . now , i told you there 's multiple ways to do this . instead of dividing both sides by 210 , you could have decided to distribute the 210 . and then you would have ended up with -- let me do another alternate way of doing it . 210 times t minus 5 times 210 . actually , let me just multiply it out so we save some space . 5 times 210 is 1,050 -- minus 1,050 is equal to 41,790 . and then you could add 1,050 to both sides . and so let me do that , 1,050 to both sides . 1,050 , not 150 . the left-hand side , you 're just going to be left with 210t . while the right-hand side , let 's see , you 're going to be 0 plus 0 is 0 . 9 plus 5 is 14 . 1 plus 7 is 8 -- 42,840 . and now you can divide both sides by 210 . now we know where this is going to go . i could do the long division again . t is going to be equal to 42,840 divided 210 , which is equal to 204 .
|
each of the remaining trees produced 210 oranges , producing a total harvest of 41,790 oranges . how many trees did macdonald 's farm have initially ? let 's let t equal what they 're asking is for .
|
how many solutions does this system of equations have ?
|
we 're in the very crowded and not very large room called the stanza della segnatura that is not only dense with people , but it 's dense with imagery . we 're looking at frescoes by raphael . painted during the high renaissance at the same time that michelangelo was painting the sistine chapel ceiling just a few doors away . this room was originally a library , part of the papal apartments , that is the apartments where the pope lived . in order to imagine what this room would have looked like at the beginning of the 16th century , imagine away all of these people and imagine instead the lower walls lined with books . and also imagine quiet which is hard to do here , and an environment of learning where you could look up at what raphael painted here on the four walls which are the four branches of human knowledge , philosophy , having to do with things of this world . the philosophy at this time also meant what we know call the sciences . on the opposite wall theology , having to do with issues relating to god and the divine . and on the two other walls , poetry and justice . so these four areas of human knowledge symbolized by allegorical figures that we see on the ceiling , and it 's so clear that a few doors away is michelangelo because raphael is clearly looking at michelangelo 's figures on the ceiling of the sistine chapel especially the prophets and the sybils . what a moment in the high renaissance all commissioned thanks to pope julius ii . and think about what it means for theology to be presented equally with human knowledge . it is this extraordinarily liberal moment in church history . when humanist 's classical learning can be united with the teachings of the church . in the center of the school of athens , the frescoe that represents philosophy , we have the two great philosophers from antiquity in the center plato and aristotle surrounded by other great thinkers and philosophers and mathematicians from antiquity . virtually , every known great figure , but let 's start with the two in the center . we can tell plato from aristotle because plato is older . plato was , in fact , aristotle 's teacher , but also because he holds one of his own books , the timaeus . and aristotle holds his book , the ethics . both of those books represent the contrasting philosophies of these two men . plato was known for being interested in the ethereal , the theoretical , that which could not be seen , and , in fact , we see him pointing upward . this idea that the world of appearances is not the final truth , that there is a realm that is based on mathematics , on pure idea that is more true than the everyday world that we see . whereas , aristotle , his student , focused his attention on the observable , the actual , the physical . you 'll notice that his palm is down , and he seems to be saying , `` no , no , no , `` let 's pay attention to what is here . '' right , to what we can see and observe in the world . in fact , if you look at the colors that each of the figures wear , they refer to this division . plato wears red and purple , the purple referring to the ether what we would call the air , the red to fire , neither of which have weight . aristotle wears blue and brown that is the colors of earth and water which have gravity , which have weight . so the philosophers on either side of plato and aristotle continue this division . on the side of plato , we see philosophers concerned with issues of the ideal . for example , on the lower left we see pythagoras the great ancient mathematician who discovered laws of harmony in music , in mathematics . this idea that there is a reality that transcends the reality that we see . compare that to the lower right where we see euclid , the figure we associate with geometry . in fact , he seems to be drawing a geometric diagram for some very eager students . but he is interested in measure , that is the idea of the practical . euclid is modeled actually on a friend of raphael 's and that 's bramante the great architect asked by pope julius ii to provide a new model for a new saint peter 's . and in fact , appropriate to his reincarnation here as euclid , bramante 's design for saint peter 's was based on a perfect geometry of circles and squares . and is really visible in the architecture that raphael constructed for the school of athens . here we see an architecture that is very bramantian , but also very ancient roman . we have coffered barrel vaults , pilasters . this is a space that ennobles the figures that it contains . and we can see representations of classical sculpture in the niches on the left , that is on the platonic side . we see apollo , the god of the sun , the god of music , the god of poetry , things that would be appropriate to the platonic . in turn on the right , we see athena , the god of war and wisdom , who presumably is involved in the more practical affairs of man . all of this seems to me to be a place that is the opposite of the medieval where knowledge was something that was passed down by authority and one had to accept it . but here , on the walls of the papal apartments , we get this image of sharing knowledge and the history of the accumulation of knowledge all with figures who move beautifully who in their bodies represent a gracefulness that is a reflection of their inner wisdom and knowledge . you 'll notice that raphael has not placed any names within the painting . the only identifiers are perhaps the titles of the books that both plato and aristotle hold , and so we 're meant to understand who these figures are through their movement , through their dress . now , the artist has parted both groups to the left and the right so that the middle foreground is fairly empty . he does this , i think , for a couple of reasons . he wants the linear perspective at the bottom of the painting to balance the strong orthogonals at the top of the painting . he wants to make way for the advancement of plato and aristotle as they walk down the stairs , but we also have two figures in the foreground in the middle . we have diogenes , and most interestingly , we have the ancient philosopher , heraclitus , who seems to be writing and thinking quietly by himself . most of the other figures in this painting are engaged with others , but not this man . he seems to be lost in his own thoughts . well , and he is writing on a block of marble . in fact , his features are those of the great artist michelangelo known for his rather lonely and brooding personality . raphael has painted him here in the same pose as the prophet isaiah on the sistine ceiling although isaiah looks up , and here michelangelo 's heraclitus decidedly looks down . and so it 's so interesting that raphael is paying homage to michelangelo the great artist here personifying heraclitus , the philosopher who believed that all things were always in flux . that figure of heraclitus was actually added later . raphael finished the frescoe , added some wet plaster , and added in that figure . we should also note that raphael included himself here . that 's the young figure looking directly out at us in a black cap , and standing among some of the most important astronomers of all time . including ptolemy , who theorized about the movements of the planets . and zoroaster , who 's holding the celestial orb . we 're so far here from the medieval idea of the artist as a craftsman . here the artist is considered an intellectual on par with some the greatest thinkers in history , who can express these important ideas . so we have dozens of figures here without any sense of stiffness or repetition . raphael , like leonardo , in the last supper divides the figures into groups . each figure overlaps and moves easily between and amongst the others . my favorite two figures are the ones just behind euclid , one leaning against the wall with his leg crossed over the other who 's hurrying and writing some notes . the other leaning over and watching . there 's a wonderful sense of intimacy there . i think it 's a scene you could see walking along the hallway of any college or university . for all the free movement of the figures , the architecture itself is using a linear perspective in a rigorous way . you can follow the orthogonal either in the pavement , or in the cornices as they recede back . so the illusion of space here in incredible . look at the way that the decoration of the greek meander seems as if it goes back in space . what 's interesting though is if this architecture is harking back to any ancient tradition , it 's harking back to the roman tradition not to the greek 's who would never use barrel vaults in this way . nearby , bramante , raphael , michelangelo could see the baths of caracalla , or the basilica of manutius and constantine . there was roman architectural ruins all over the city that resembled what raphael has painted here . it 's so extraordinary that we 're celebrating here , the pantheon of great pagan thinkers . none of these men were christians . let 's take a quick look at the frescoes that 's opposite the school of athens known as the dispute . this frescoe represents theology , the study of the divine . figures here are divided between the heavenly and the earthly . close to the top we see god the father in the dome of heaven . below him , christ in this marvelous full-body halo , or mandorla , and he 's surrounded by the virgin mary on his right , and st. john the baptist on his left . just below , a dove against another gold disk , and this is the holy spirit , so all three together are the trinity . on either side of the dove are the four books of the gospels , matthew , mark , luke and john , that tell the story of the life of christ . on that wonderful bench of clouds sit prophets and saints . and we can actually recognize , for instance , moses holding the 10 commandments . and then another circle below contains the host , or the bread that is miraculously the body of christ during the mass . the bread functions as a link between heaven and earth . we can see how separated heaven and earth are in this fresco , and how important that link is . the figures along the bottom are popes , and bishops , and cardinals , and members of various religious orders . the fathers of the church , we can make out a portrait of dante , the great medieval poet . we have a sense of the figures on the bottom of the frescoe , coming to divine knowledge through the miracle of the host , and two figures on either end seem to be moving away from that divine knowledge . but there 's efforts being made to turn them around , to bring them back . so here , in the stanza della segnatura a room that functioned as the library for pope julius ii , a celebration of all aspects of human knowledge .
|
plato was , in fact , aristotle 's teacher , but also because he holds one of his own books , the timaeus . and aristotle holds his book , the ethics . both of those books represent the contrasting philosophies of these two men .
|
who is the figure sprawled on the steps by himself in front of aristotle and plata , and what does he signify ?
|
we 're in the very crowded and not very large room called the stanza della segnatura that is not only dense with people , but it 's dense with imagery . we 're looking at frescoes by raphael . painted during the high renaissance at the same time that michelangelo was painting the sistine chapel ceiling just a few doors away . this room was originally a library , part of the papal apartments , that is the apartments where the pope lived . in order to imagine what this room would have looked like at the beginning of the 16th century , imagine away all of these people and imagine instead the lower walls lined with books . and also imagine quiet which is hard to do here , and an environment of learning where you could look up at what raphael painted here on the four walls which are the four branches of human knowledge , philosophy , having to do with things of this world . the philosophy at this time also meant what we know call the sciences . on the opposite wall theology , having to do with issues relating to god and the divine . and on the two other walls , poetry and justice . so these four areas of human knowledge symbolized by allegorical figures that we see on the ceiling , and it 's so clear that a few doors away is michelangelo because raphael is clearly looking at michelangelo 's figures on the ceiling of the sistine chapel especially the prophets and the sybils . what a moment in the high renaissance all commissioned thanks to pope julius ii . and think about what it means for theology to be presented equally with human knowledge . it is this extraordinarily liberal moment in church history . when humanist 's classical learning can be united with the teachings of the church . in the center of the school of athens , the frescoe that represents philosophy , we have the two great philosophers from antiquity in the center plato and aristotle surrounded by other great thinkers and philosophers and mathematicians from antiquity . virtually , every known great figure , but let 's start with the two in the center . we can tell plato from aristotle because plato is older . plato was , in fact , aristotle 's teacher , but also because he holds one of his own books , the timaeus . and aristotle holds his book , the ethics . both of those books represent the contrasting philosophies of these two men . plato was known for being interested in the ethereal , the theoretical , that which could not be seen , and , in fact , we see him pointing upward . this idea that the world of appearances is not the final truth , that there is a realm that is based on mathematics , on pure idea that is more true than the everyday world that we see . whereas , aristotle , his student , focused his attention on the observable , the actual , the physical . you 'll notice that his palm is down , and he seems to be saying , `` no , no , no , `` let 's pay attention to what is here . '' right , to what we can see and observe in the world . in fact , if you look at the colors that each of the figures wear , they refer to this division . plato wears red and purple , the purple referring to the ether what we would call the air , the red to fire , neither of which have weight . aristotle wears blue and brown that is the colors of earth and water which have gravity , which have weight . so the philosophers on either side of plato and aristotle continue this division . on the side of plato , we see philosophers concerned with issues of the ideal . for example , on the lower left we see pythagoras the great ancient mathematician who discovered laws of harmony in music , in mathematics . this idea that there is a reality that transcends the reality that we see . compare that to the lower right where we see euclid , the figure we associate with geometry . in fact , he seems to be drawing a geometric diagram for some very eager students . but he is interested in measure , that is the idea of the practical . euclid is modeled actually on a friend of raphael 's and that 's bramante the great architect asked by pope julius ii to provide a new model for a new saint peter 's . and in fact , appropriate to his reincarnation here as euclid , bramante 's design for saint peter 's was based on a perfect geometry of circles and squares . and is really visible in the architecture that raphael constructed for the school of athens . here we see an architecture that is very bramantian , but also very ancient roman . we have coffered barrel vaults , pilasters . this is a space that ennobles the figures that it contains . and we can see representations of classical sculpture in the niches on the left , that is on the platonic side . we see apollo , the god of the sun , the god of music , the god of poetry , things that would be appropriate to the platonic . in turn on the right , we see athena , the god of war and wisdom , who presumably is involved in the more practical affairs of man . all of this seems to me to be a place that is the opposite of the medieval where knowledge was something that was passed down by authority and one had to accept it . but here , on the walls of the papal apartments , we get this image of sharing knowledge and the history of the accumulation of knowledge all with figures who move beautifully who in their bodies represent a gracefulness that is a reflection of their inner wisdom and knowledge . you 'll notice that raphael has not placed any names within the painting . the only identifiers are perhaps the titles of the books that both plato and aristotle hold , and so we 're meant to understand who these figures are through their movement , through their dress . now , the artist has parted both groups to the left and the right so that the middle foreground is fairly empty . he does this , i think , for a couple of reasons . he wants the linear perspective at the bottom of the painting to balance the strong orthogonals at the top of the painting . he wants to make way for the advancement of plato and aristotle as they walk down the stairs , but we also have two figures in the foreground in the middle . we have diogenes , and most interestingly , we have the ancient philosopher , heraclitus , who seems to be writing and thinking quietly by himself . most of the other figures in this painting are engaged with others , but not this man . he seems to be lost in his own thoughts . well , and he is writing on a block of marble . in fact , his features are those of the great artist michelangelo known for his rather lonely and brooding personality . raphael has painted him here in the same pose as the prophet isaiah on the sistine ceiling although isaiah looks up , and here michelangelo 's heraclitus decidedly looks down . and so it 's so interesting that raphael is paying homage to michelangelo the great artist here personifying heraclitus , the philosopher who believed that all things were always in flux . that figure of heraclitus was actually added later . raphael finished the frescoe , added some wet plaster , and added in that figure . we should also note that raphael included himself here . that 's the young figure looking directly out at us in a black cap , and standing among some of the most important astronomers of all time . including ptolemy , who theorized about the movements of the planets . and zoroaster , who 's holding the celestial orb . we 're so far here from the medieval idea of the artist as a craftsman . here the artist is considered an intellectual on par with some the greatest thinkers in history , who can express these important ideas . so we have dozens of figures here without any sense of stiffness or repetition . raphael , like leonardo , in the last supper divides the figures into groups . each figure overlaps and moves easily between and amongst the others . my favorite two figures are the ones just behind euclid , one leaning against the wall with his leg crossed over the other who 's hurrying and writing some notes . the other leaning over and watching . there 's a wonderful sense of intimacy there . i think it 's a scene you could see walking along the hallway of any college or university . for all the free movement of the figures , the architecture itself is using a linear perspective in a rigorous way . you can follow the orthogonal either in the pavement , or in the cornices as they recede back . so the illusion of space here in incredible . look at the way that the decoration of the greek meander seems as if it goes back in space . what 's interesting though is if this architecture is harking back to any ancient tradition , it 's harking back to the roman tradition not to the greek 's who would never use barrel vaults in this way . nearby , bramante , raphael , michelangelo could see the baths of caracalla , or the basilica of manutius and constantine . there was roman architectural ruins all over the city that resembled what raphael has painted here . it 's so extraordinary that we 're celebrating here , the pantheon of great pagan thinkers . none of these men were christians . let 's take a quick look at the frescoes that 's opposite the school of athens known as the dispute . this frescoe represents theology , the study of the divine . figures here are divided between the heavenly and the earthly . close to the top we see god the father in the dome of heaven . below him , christ in this marvelous full-body halo , or mandorla , and he 's surrounded by the virgin mary on his right , and st. john the baptist on his left . just below , a dove against another gold disk , and this is the holy spirit , so all three together are the trinity . on either side of the dove are the four books of the gospels , matthew , mark , luke and john , that tell the story of the life of christ . on that wonderful bench of clouds sit prophets and saints . and we can actually recognize , for instance , moses holding the 10 commandments . and then another circle below contains the host , or the bread that is miraculously the body of christ during the mass . the bread functions as a link between heaven and earth . we can see how separated heaven and earth are in this fresco , and how important that link is . the figures along the bottom are popes , and bishops , and cardinals , and members of various religious orders . the fathers of the church , we can make out a portrait of dante , the great medieval poet . we have a sense of the figures on the bottom of the frescoe , coming to divine knowledge through the miracle of the host , and two figures on either end seem to be moving away from that divine knowledge . but there 's efforts being made to turn them around , to bring them back . so here , in the stanza della segnatura a room that functioned as the library for pope julius ii , a celebration of all aspects of human knowledge .
|
plato was , in fact , aristotle 's teacher , but also because he holds one of his own books , the timaeus . and aristotle holds his book , the ethics . both of those books represent the contrasting philosophies of these two men .
|
with so many of this cast being portraits of renaissance superstars , do we know is aristotle was a portrait ?
|
we 're in the very crowded and not very large room called the stanza della segnatura that is not only dense with people , but it 's dense with imagery . we 're looking at frescoes by raphael . painted during the high renaissance at the same time that michelangelo was painting the sistine chapel ceiling just a few doors away . this room was originally a library , part of the papal apartments , that is the apartments where the pope lived . in order to imagine what this room would have looked like at the beginning of the 16th century , imagine away all of these people and imagine instead the lower walls lined with books . and also imagine quiet which is hard to do here , and an environment of learning where you could look up at what raphael painted here on the four walls which are the four branches of human knowledge , philosophy , having to do with things of this world . the philosophy at this time also meant what we know call the sciences . on the opposite wall theology , having to do with issues relating to god and the divine . and on the two other walls , poetry and justice . so these four areas of human knowledge symbolized by allegorical figures that we see on the ceiling , and it 's so clear that a few doors away is michelangelo because raphael is clearly looking at michelangelo 's figures on the ceiling of the sistine chapel especially the prophets and the sybils . what a moment in the high renaissance all commissioned thanks to pope julius ii . and think about what it means for theology to be presented equally with human knowledge . it is this extraordinarily liberal moment in church history . when humanist 's classical learning can be united with the teachings of the church . in the center of the school of athens , the frescoe that represents philosophy , we have the two great philosophers from antiquity in the center plato and aristotle surrounded by other great thinkers and philosophers and mathematicians from antiquity . virtually , every known great figure , but let 's start with the two in the center . we can tell plato from aristotle because plato is older . plato was , in fact , aristotle 's teacher , but also because he holds one of his own books , the timaeus . and aristotle holds his book , the ethics . both of those books represent the contrasting philosophies of these two men . plato was known for being interested in the ethereal , the theoretical , that which could not be seen , and , in fact , we see him pointing upward . this idea that the world of appearances is not the final truth , that there is a realm that is based on mathematics , on pure idea that is more true than the everyday world that we see . whereas , aristotle , his student , focused his attention on the observable , the actual , the physical . you 'll notice that his palm is down , and he seems to be saying , `` no , no , no , `` let 's pay attention to what is here . '' right , to what we can see and observe in the world . in fact , if you look at the colors that each of the figures wear , they refer to this division . plato wears red and purple , the purple referring to the ether what we would call the air , the red to fire , neither of which have weight . aristotle wears blue and brown that is the colors of earth and water which have gravity , which have weight . so the philosophers on either side of plato and aristotle continue this division . on the side of plato , we see philosophers concerned with issues of the ideal . for example , on the lower left we see pythagoras the great ancient mathematician who discovered laws of harmony in music , in mathematics . this idea that there is a reality that transcends the reality that we see . compare that to the lower right where we see euclid , the figure we associate with geometry . in fact , he seems to be drawing a geometric diagram for some very eager students . but he is interested in measure , that is the idea of the practical . euclid is modeled actually on a friend of raphael 's and that 's bramante the great architect asked by pope julius ii to provide a new model for a new saint peter 's . and in fact , appropriate to his reincarnation here as euclid , bramante 's design for saint peter 's was based on a perfect geometry of circles and squares . and is really visible in the architecture that raphael constructed for the school of athens . here we see an architecture that is very bramantian , but also very ancient roman . we have coffered barrel vaults , pilasters . this is a space that ennobles the figures that it contains . and we can see representations of classical sculpture in the niches on the left , that is on the platonic side . we see apollo , the god of the sun , the god of music , the god of poetry , things that would be appropriate to the platonic . in turn on the right , we see athena , the god of war and wisdom , who presumably is involved in the more practical affairs of man . all of this seems to me to be a place that is the opposite of the medieval where knowledge was something that was passed down by authority and one had to accept it . but here , on the walls of the papal apartments , we get this image of sharing knowledge and the history of the accumulation of knowledge all with figures who move beautifully who in their bodies represent a gracefulness that is a reflection of their inner wisdom and knowledge . you 'll notice that raphael has not placed any names within the painting . the only identifiers are perhaps the titles of the books that both plato and aristotle hold , and so we 're meant to understand who these figures are through their movement , through their dress . now , the artist has parted both groups to the left and the right so that the middle foreground is fairly empty . he does this , i think , for a couple of reasons . he wants the linear perspective at the bottom of the painting to balance the strong orthogonals at the top of the painting . he wants to make way for the advancement of plato and aristotle as they walk down the stairs , but we also have two figures in the foreground in the middle . we have diogenes , and most interestingly , we have the ancient philosopher , heraclitus , who seems to be writing and thinking quietly by himself . most of the other figures in this painting are engaged with others , but not this man . he seems to be lost in his own thoughts . well , and he is writing on a block of marble . in fact , his features are those of the great artist michelangelo known for his rather lonely and brooding personality . raphael has painted him here in the same pose as the prophet isaiah on the sistine ceiling although isaiah looks up , and here michelangelo 's heraclitus decidedly looks down . and so it 's so interesting that raphael is paying homage to michelangelo the great artist here personifying heraclitus , the philosopher who believed that all things were always in flux . that figure of heraclitus was actually added later . raphael finished the frescoe , added some wet plaster , and added in that figure . we should also note that raphael included himself here . that 's the young figure looking directly out at us in a black cap , and standing among some of the most important astronomers of all time . including ptolemy , who theorized about the movements of the planets . and zoroaster , who 's holding the celestial orb . we 're so far here from the medieval idea of the artist as a craftsman . here the artist is considered an intellectual on par with some the greatest thinkers in history , who can express these important ideas . so we have dozens of figures here without any sense of stiffness or repetition . raphael , like leonardo , in the last supper divides the figures into groups . each figure overlaps and moves easily between and amongst the others . my favorite two figures are the ones just behind euclid , one leaning against the wall with his leg crossed over the other who 's hurrying and writing some notes . the other leaning over and watching . there 's a wonderful sense of intimacy there . i think it 's a scene you could see walking along the hallway of any college or university . for all the free movement of the figures , the architecture itself is using a linear perspective in a rigorous way . you can follow the orthogonal either in the pavement , or in the cornices as they recede back . so the illusion of space here in incredible . look at the way that the decoration of the greek meander seems as if it goes back in space . what 's interesting though is if this architecture is harking back to any ancient tradition , it 's harking back to the roman tradition not to the greek 's who would never use barrel vaults in this way . nearby , bramante , raphael , michelangelo could see the baths of caracalla , or the basilica of manutius and constantine . there was roman architectural ruins all over the city that resembled what raphael has painted here . it 's so extraordinary that we 're celebrating here , the pantheon of great pagan thinkers . none of these men were christians . let 's take a quick look at the frescoes that 's opposite the school of athens known as the dispute . this frescoe represents theology , the study of the divine . figures here are divided between the heavenly and the earthly . close to the top we see god the father in the dome of heaven . below him , christ in this marvelous full-body halo , or mandorla , and he 's surrounded by the virgin mary on his right , and st. john the baptist on his left . just below , a dove against another gold disk , and this is the holy spirit , so all three together are the trinity . on either side of the dove are the four books of the gospels , matthew , mark , luke and john , that tell the story of the life of christ . on that wonderful bench of clouds sit prophets and saints . and we can actually recognize , for instance , moses holding the 10 commandments . and then another circle below contains the host , or the bread that is miraculously the body of christ during the mass . the bread functions as a link between heaven and earth . we can see how separated heaven and earth are in this fresco , and how important that link is . the figures along the bottom are popes , and bishops , and cardinals , and members of various religious orders . the fathers of the church , we can make out a portrait of dante , the great medieval poet . we have a sense of the figures on the bottom of the frescoe , coming to divine knowledge through the miracle of the host , and two figures on either end seem to be moving away from that divine knowledge . but there 's efforts being made to turn them around , to bring them back . so here , in the stanza della segnatura a room that functioned as the library for pope julius ii , a celebration of all aspects of human knowledge .
|
and in fact , appropriate to his reincarnation here as euclid , bramante 's design for saint peter 's was based on a perfect geometry of circles and squares . and is really visible in the architecture that raphael constructed for the school of athens . here we see an architecture that is very bramantian , but also very ancient roman .
|
when raphael transferred his drawing of the school of athens to the wall for painting , what substance did he force through perforations in the paper ?
|
we 're in the very crowded and not very large room called the stanza della segnatura that is not only dense with people , but it 's dense with imagery . we 're looking at frescoes by raphael . painted during the high renaissance at the same time that michelangelo was painting the sistine chapel ceiling just a few doors away . this room was originally a library , part of the papal apartments , that is the apartments where the pope lived . in order to imagine what this room would have looked like at the beginning of the 16th century , imagine away all of these people and imagine instead the lower walls lined with books . and also imagine quiet which is hard to do here , and an environment of learning where you could look up at what raphael painted here on the four walls which are the four branches of human knowledge , philosophy , having to do with things of this world . the philosophy at this time also meant what we know call the sciences . on the opposite wall theology , having to do with issues relating to god and the divine . and on the two other walls , poetry and justice . so these four areas of human knowledge symbolized by allegorical figures that we see on the ceiling , and it 's so clear that a few doors away is michelangelo because raphael is clearly looking at michelangelo 's figures on the ceiling of the sistine chapel especially the prophets and the sybils . what a moment in the high renaissance all commissioned thanks to pope julius ii . and think about what it means for theology to be presented equally with human knowledge . it is this extraordinarily liberal moment in church history . when humanist 's classical learning can be united with the teachings of the church . in the center of the school of athens , the frescoe that represents philosophy , we have the two great philosophers from antiquity in the center plato and aristotle surrounded by other great thinkers and philosophers and mathematicians from antiquity . virtually , every known great figure , but let 's start with the two in the center . we can tell plato from aristotle because plato is older . plato was , in fact , aristotle 's teacher , but also because he holds one of his own books , the timaeus . and aristotle holds his book , the ethics . both of those books represent the contrasting philosophies of these two men . plato was known for being interested in the ethereal , the theoretical , that which could not be seen , and , in fact , we see him pointing upward . this idea that the world of appearances is not the final truth , that there is a realm that is based on mathematics , on pure idea that is more true than the everyday world that we see . whereas , aristotle , his student , focused his attention on the observable , the actual , the physical . you 'll notice that his palm is down , and he seems to be saying , `` no , no , no , `` let 's pay attention to what is here . '' right , to what we can see and observe in the world . in fact , if you look at the colors that each of the figures wear , they refer to this division . plato wears red and purple , the purple referring to the ether what we would call the air , the red to fire , neither of which have weight . aristotle wears blue and brown that is the colors of earth and water which have gravity , which have weight . so the philosophers on either side of plato and aristotle continue this division . on the side of plato , we see philosophers concerned with issues of the ideal . for example , on the lower left we see pythagoras the great ancient mathematician who discovered laws of harmony in music , in mathematics . this idea that there is a reality that transcends the reality that we see . compare that to the lower right where we see euclid , the figure we associate with geometry . in fact , he seems to be drawing a geometric diagram for some very eager students . but he is interested in measure , that is the idea of the practical . euclid is modeled actually on a friend of raphael 's and that 's bramante the great architect asked by pope julius ii to provide a new model for a new saint peter 's . and in fact , appropriate to his reincarnation here as euclid , bramante 's design for saint peter 's was based on a perfect geometry of circles and squares . and is really visible in the architecture that raphael constructed for the school of athens . here we see an architecture that is very bramantian , but also very ancient roman . we have coffered barrel vaults , pilasters . this is a space that ennobles the figures that it contains . and we can see representations of classical sculpture in the niches on the left , that is on the platonic side . we see apollo , the god of the sun , the god of music , the god of poetry , things that would be appropriate to the platonic . in turn on the right , we see athena , the god of war and wisdom , who presumably is involved in the more practical affairs of man . all of this seems to me to be a place that is the opposite of the medieval where knowledge was something that was passed down by authority and one had to accept it . but here , on the walls of the papal apartments , we get this image of sharing knowledge and the history of the accumulation of knowledge all with figures who move beautifully who in their bodies represent a gracefulness that is a reflection of their inner wisdom and knowledge . you 'll notice that raphael has not placed any names within the painting . the only identifiers are perhaps the titles of the books that both plato and aristotle hold , and so we 're meant to understand who these figures are through their movement , through their dress . now , the artist has parted both groups to the left and the right so that the middle foreground is fairly empty . he does this , i think , for a couple of reasons . he wants the linear perspective at the bottom of the painting to balance the strong orthogonals at the top of the painting . he wants to make way for the advancement of plato and aristotle as they walk down the stairs , but we also have two figures in the foreground in the middle . we have diogenes , and most interestingly , we have the ancient philosopher , heraclitus , who seems to be writing and thinking quietly by himself . most of the other figures in this painting are engaged with others , but not this man . he seems to be lost in his own thoughts . well , and he is writing on a block of marble . in fact , his features are those of the great artist michelangelo known for his rather lonely and brooding personality . raphael has painted him here in the same pose as the prophet isaiah on the sistine ceiling although isaiah looks up , and here michelangelo 's heraclitus decidedly looks down . and so it 's so interesting that raphael is paying homage to michelangelo the great artist here personifying heraclitus , the philosopher who believed that all things were always in flux . that figure of heraclitus was actually added later . raphael finished the frescoe , added some wet plaster , and added in that figure . we should also note that raphael included himself here . that 's the young figure looking directly out at us in a black cap , and standing among some of the most important astronomers of all time . including ptolemy , who theorized about the movements of the planets . and zoroaster , who 's holding the celestial orb . we 're so far here from the medieval idea of the artist as a craftsman . here the artist is considered an intellectual on par with some the greatest thinkers in history , who can express these important ideas . so we have dozens of figures here without any sense of stiffness or repetition . raphael , like leonardo , in the last supper divides the figures into groups . each figure overlaps and moves easily between and amongst the others . my favorite two figures are the ones just behind euclid , one leaning against the wall with his leg crossed over the other who 's hurrying and writing some notes . the other leaning over and watching . there 's a wonderful sense of intimacy there . i think it 's a scene you could see walking along the hallway of any college or university . for all the free movement of the figures , the architecture itself is using a linear perspective in a rigorous way . you can follow the orthogonal either in the pavement , or in the cornices as they recede back . so the illusion of space here in incredible . look at the way that the decoration of the greek meander seems as if it goes back in space . what 's interesting though is if this architecture is harking back to any ancient tradition , it 's harking back to the roman tradition not to the greek 's who would never use barrel vaults in this way . nearby , bramante , raphael , michelangelo could see the baths of caracalla , or the basilica of manutius and constantine . there was roman architectural ruins all over the city that resembled what raphael has painted here . it 's so extraordinary that we 're celebrating here , the pantheon of great pagan thinkers . none of these men were christians . let 's take a quick look at the frescoes that 's opposite the school of athens known as the dispute . this frescoe represents theology , the study of the divine . figures here are divided between the heavenly and the earthly . close to the top we see god the father in the dome of heaven . below him , christ in this marvelous full-body halo , or mandorla , and he 's surrounded by the virgin mary on his right , and st. john the baptist on his left . just below , a dove against another gold disk , and this is the holy spirit , so all three together are the trinity . on either side of the dove are the four books of the gospels , matthew , mark , luke and john , that tell the story of the life of christ . on that wonderful bench of clouds sit prophets and saints . and we can actually recognize , for instance , moses holding the 10 commandments . and then another circle below contains the host , or the bread that is miraculously the body of christ during the mass . the bread functions as a link between heaven and earth . we can see how separated heaven and earth are in this fresco , and how important that link is . the figures along the bottom are popes , and bishops , and cardinals , and members of various religious orders . the fathers of the church , we can make out a portrait of dante , the great medieval poet . we have a sense of the figures on the bottom of the frescoe , coming to divine knowledge through the miracle of the host , and two figures on either end seem to be moving away from that divine knowledge . but there 's efforts being made to turn them around , to bring them back . so here , in the stanza della segnatura a room that functioned as the library for pope julius ii , a celebration of all aspects of human knowledge .
|
and in fact , appropriate to his reincarnation here as euclid , bramante 's design for saint peter 's was based on a perfect geometry of circles and squares . and is really visible in the architecture that raphael constructed for the school of athens . here we see an architecture that is very bramantian , but also very ancient roman .
|
when raphael transferred his drawing of the school of athens to the wall for painting , what substance did he force through perforations in the paper ?
|
we 're in the very crowded and not very large room called the stanza della segnatura that is not only dense with people , but it 's dense with imagery . we 're looking at frescoes by raphael . painted during the high renaissance at the same time that michelangelo was painting the sistine chapel ceiling just a few doors away . this room was originally a library , part of the papal apartments , that is the apartments where the pope lived . in order to imagine what this room would have looked like at the beginning of the 16th century , imagine away all of these people and imagine instead the lower walls lined with books . and also imagine quiet which is hard to do here , and an environment of learning where you could look up at what raphael painted here on the four walls which are the four branches of human knowledge , philosophy , having to do with things of this world . the philosophy at this time also meant what we know call the sciences . on the opposite wall theology , having to do with issues relating to god and the divine . and on the two other walls , poetry and justice . so these four areas of human knowledge symbolized by allegorical figures that we see on the ceiling , and it 's so clear that a few doors away is michelangelo because raphael is clearly looking at michelangelo 's figures on the ceiling of the sistine chapel especially the prophets and the sybils . what a moment in the high renaissance all commissioned thanks to pope julius ii . and think about what it means for theology to be presented equally with human knowledge . it is this extraordinarily liberal moment in church history . when humanist 's classical learning can be united with the teachings of the church . in the center of the school of athens , the frescoe that represents philosophy , we have the two great philosophers from antiquity in the center plato and aristotle surrounded by other great thinkers and philosophers and mathematicians from antiquity . virtually , every known great figure , but let 's start with the two in the center . we can tell plato from aristotle because plato is older . plato was , in fact , aristotle 's teacher , but also because he holds one of his own books , the timaeus . and aristotle holds his book , the ethics . both of those books represent the contrasting philosophies of these two men . plato was known for being interested in the ethereal , the theoretical , that which could not be seen , and , in fact , we see him pointing upward . this idea that the world of appearances is not the final truth , that there is a realm that is based on mathematics , on pure idea that is more true than the everyday world that we see . whereas , aristotle , his student , focused his attention on the observable , the actual , the physical . you 'll notice that his palm is down , and he seems to be saying , `` no , no , no , `` let 's pay attention to what is here . '' right , to what we can see and observe in the world . in fact , if you look at the colors that each of the figures wear , they refer to this division . plato wears red and purple , the purple referring to the ether what we would call the air , the red to fire , neither of which have weight . aristotle wears blue and brown that is the colors of earth and water which have gravity , which have weight . so the philosophers on either side of plato and aristotle continue this division . on the side of plato , we see philosophers concerned with issues of the ideal . for example , on the lower left we see pythagoras the great ancient mathematician who discovered laws of harmony in music , in mathematics . this idea that there is a reality that transcends the reality that we see . compare that to the lower right where we see euclid , the figure we associate with geometry . in fact , he seems to be drawing a geometric diagram for some very eager students . but he is interested in measure , that is the idea of the practical . euclid is modeled actually on a friend of raphael 's and that 's bramante the great architect asked by pope julius ii to provide a new model for a new saint peter 's . and in fact , appropriate to his reincarnation here as euclid , bramante 's design for saint peter 's was based on a perfect geometry of circles and squares . and is really visible in the architecture that raphael constructed for the school of athens . here we see an architecture that is very bramantian , but also very ancient roman . we have coffered barrel vaults , pilasters . this is a space that ennobles the figures that it contains . and we can see representations of classical sculpture in the niches on the left , that is on the platonic side . we see apollo , the god of the sun , the god of music , the god of poetry , things that would be appropriate to the platonic . in turn on the right , we see athena , the god of war and wisdom , who presumably is involved in the more practical affairs of man . all of this seems to me to be a place that is the opposite of the medieval where knowledge was something that was passed down by authority and one had to accept it . but here , on the walls of the papal apartments , we get this image of sharing knowledge and the history of the accumulation of knowledge all with figures who move beautifully who in their bodies represent a gracefulness that is a reflection of their inner wisdom and knowledge . you 'll notice that raphael has not placed any names within the painting . the only identifiers are perhaps the titles of the books that both plato and aristotle hold , and so we 're meant to understand who these figures are through their movement , through their dress . now , the artist has parted both groups to the left and the right so that the middle foreground is fairly empty . he does this , i think , for a couple of reasons . he wants the linear perspective at the bottom of the painting to balance the strong orthogonals at the top of the painting . he wants to make way for the advancement of plato and aristotle as they walk down the stairs , but we also have two figures in the foreground in the middle . we have diogenes , and most interestingly , we have the ancient philosopher , heraclitus , who seems to be writing and thinking quietly by himself . most of the other figures in this painting are engaged with others , but not this man . he seems to be lost in his own thoughts . well , and he is writing on a block of marble . in fact , his features are those of the great artist michelangelo known for his rather lonely and brooding personality . raphael has painted him here in the same pose as the prophet isaiah on the sistine ceiling although isaiah looks up , and here michelangelo 's heraclitus decidedly looks down . and so it 's so interesting that raphael is paying homage to michelangelo the great artist here personifying heraclitus , the philosopher who believed that all things were always in flux . that figure of heraclitus was actually added later . raphael finished the frescoe , added some wet plaster , and added in that figure . we should also note that raphael included himself here . that 's the young figure looking directly out at us in a black cap , and standing among some of the most important astronomers of all time . including ptolemy , who theorized about the movements of the planets . and zoroaster , who 's holding the celestial orb . we 're so far here from the medieval idea of the artist as a craftsman . here the artist is considered an intellectual on par with some the greatest thinkers in history , who can express these important ideas . so we have dozens of figures here without any sense of stiffness or repetition . raphael , like leonardo , in the last supper divides the figures into groups . each figure overlaps and moves easily between and amongst the others . my favorite two figures are the ones just behind euclid , one leaning against the wall with his leg crossed over the other who 's hurrying and writing some notes . the other leaning over and watching . there 's a wonderful sense of intimacy there . i think it 's a scene you could see walking along the hallway of any college or university . for all the free movement of the figures , the architecture itself is using a linear perspective in a rigorous way . you can follow the orthogonal either in the pavement , or in the cornices as they recede back . so the illusion of space here in incredible . look at the way that the decoration of the greek meander seems as if it goes back in space . what 's interesting though is if this architecture is harking back to any ancient tradition , it 's harking back to the roman tradition not to the greek 's who would never use barrel vaults in this way . nearby , bramante , raphael , michelangelo could see the baths of caracalla , or the basilica of manutius and constantine . there was roman architectural ruins all over the city that resembled what raphael has painted here . it 's so extraordinary that we 're celebrating here , the pantheon of great pagan thinkers . none of these men were christians . let 's take a quick look at the frescoes that 's opposite the school of athens known as the dispute . this frescoe represents theology , the study of the divine . figures here are divided between the heavenly and the earthly . close to the top we see god the father in the dome of heaven . below him , christ in this marvelous full-body halo , or mandorla , and he 's surrounded by the virgin mary on his right , and st. john the baptist on his left . just below , a dove against another gold disk , and this is the holy spirit , so all three together are the trinity . on either side of the dove are the four books of the gospels , matthew , mark , luke and john , that tell the story of the life of christ . on that wonderful bench of clouds sit prophets and saints . and we can actually recognize , for instance , moses holding the 10 commandments . and then another circle below contains the host , or the bread that is miraculously the body of christ during the mass . the bread functions as a link between heaven and earth . we can see how separated heaven and earth are in this fresco , and how important that link is . the figures along the bottom are popes , and bishops , and cardinals , and members of various religious orders . the fathers of the church , we can make out a portrait of dante , the great medieval poet . we have a sense of the figures on the bottom of the frescoe , coming to divine knowledge through the miracle of the host , and two figures on either end seem to be moving away from that divine knowledge . but there 's efforts being made to turn them around , to bring them back . so here , in the stanza della segnatura a room that functioned as the library for pope julius ii , a celebration of all aspects of human knowledge .
|
we 're in the very crowded and not very large room called the stanza della segnatura that is not only dense with people , but it 's dense with imagery . we 're looking at frescoes by raphael .
|
how is reform shown throughout this piece ?
|
we 're in the very crowded and not very large room called the stanza della segnatura that is not only dense with people , but it 's dense with imagery . we 're looking at frescoes by raphael . painted during the high renaissance at the same time that michelangelo was painting the sistine chapel ceiling just a few doors away . this room was originally a library , part of the papal apartments , that is the apartments where the pope lived . in order to imagine what this room would have looked like at the beginning of the 16th century , imagine away all of these people and imagine instead the lower walls lined with books . and also imagine quiet which is hard to do here , and an environment of learning where you could look up at what raphael painted here on the four walls which are the four branches of human knowledge , philosophy , having to do with things of this world . the philosophy at this time also meant what we know call the sciences . on the opposite wall theology , having to do with issues relating to god and the divine . and on the two other walls , poetry and justice . so these four areas of human knowledge symbolized by allegorical figures that we see on the ceiling , and it 's so clear that a few doors away is michelangelo because raphael is clearly looking at michelangelo 's figures on the ceiling of the sistine chapel especially the prophets and the sybils . what a moment in the high renaissance all commissioned thanks to pope julius ii . and think about what it means for theology to be presented equally with human knowledge . it is this extraordinarily liberal moment in church history . when humanist 's classical learning can be united with the teachings of the church . in the center of the school of athens , the frescoe that represents philosophy , we have the two great philosophers from antiquity in the center plato and aristotle surrounded by other great thinkers and philosophers and mathematicians from antiquity . virtually , every known great figure , but let 's start with the two in the center . we can tell plato from aristotle because plato is older . plato was , in fact , aristotle 's teacher , but also because he holds one of his own books , the timaeus . and aristotle holds his book , the ethics . both of those books represent the contrasting philosophies of these two men . plato was known for being interested in the ethereal , the theoretical , that which could not be seen , and , in fact , we see him pointing upward . this idea that the world of appearances is not the final truth , that there is a realm that is based on mathematics , on pure idea that is more true than the everyday world that we see . whereas , aristotle , his student , focused his attention on the observable , the actual , the physical . you 'll notice that his palm is down , and he seems to be saying , `` no , no , no , `` let 's pay attention to what is here . '' right , to what we can see and observe in the world . in fact , if you look at the colors that each of the figures wear , they refer to this division . plato wears red and purple , the purple referring to the ether what we would call the air , the red to fire , neither of which have weight . aristotle wears blue and brown that is the colors of earth and water which have gravity , which have weight . so the philosophers on either side of plato and aristotle continue this division . on the side of plato , we see philosophers concerned with issues of the ideal . for example , on the lower left we see pythagoras the great ancient mathematician who discovered laws of harmony in music , in mathematics . this idea that there is a reality that transcends the reality that we see . compare that to the lower right where we see euclid , the figure we associate with geometry . in fact , he seems to be drawing a geometric diagram for some very eager students . but he is interested in measure , that is the idea of the practical . euclid is modeled actually on a friend of raphael 's and that 's bramante the great architect asked by pope julius ii to provide a new model for a new saint peter 's . and in fact , appropriate to his reincarnation here as euclid , bramante 's design for saint peter 's was based on a perfect geometry of circles and squares . and is really visible in the architecture that raphael constructed for the school of athens . here we see an architecture that is very bramantian , but also very ancient roman . we have coffered barrel vaults , pilasters . this is a space that ennobles the figures that it contains . and we can see representations of classical sculpture in the niches on the left , that is on the platonic side . we see apollo , the god of the sun , the god of music , the god of poetry , things that would be appropriate to the platonic . in turn on the right , we see athena , the god of war and wisdom , who presumably is involved in the more practical affairs of man . all of this seems to me to be a place that is the opposite of the medieval where knowledge was something that was passed down by authority and one had to accept it . but here , on the walls of the papal apartments , we get this image of sharing knowledge and the history of the accumulation of knowledge all with figures who move beautifully who in their bodies represent a gracefulness that is a reflection of their inner wisdom and knowledge . you 'll notice that raphael has not placed any names within the painting . the only identifiers are perhaps the titles of the books that both plato and aristotle hold , and so we 're meant to understand who these figures are through their movement , through their dress . now , the artist has parted both groups to the left and the right so that the middle foreground is fairly empty . he does this , i think , for a couple of reasons . he wants the linear perspective at the bottom of the painting to balance the strong orthogonals at the top of the painting . he wants to make way for the advancement of plato and aristotle as they walk down the stairs , but we also have two figures in the foreground in the middle . we have diogenes , and most interestingly , we have the ancient philosopher , heraclitus , who seems to be writing and thinking quietly by himself . most of the other figures in this painting are engaged with others , but not this man . he seems to be lost in his own thoughts . well , and he is writing on a block of marble . in fact , his features are those of the great artist michelangelo known for his rather lonely and brooding personality . raphael has painted him here in the same pose as the prophet isaiah on the sistine ceiling although isaiah looks up , and here michelangelo 's heraclitus decidedly looks down . and so it 's so interesting that raphael is paying homage to michelangelo the great artist here personifying heraclitus , the philosopher who believed that all things were always in flux . that figure of heraclitus was actually added later . raphael finished the frescoe , added some wet plaster , and added in that figure . we should also note that raphael included himself here . that 's the young figure looking directly out at us in a black cap , and standing among some of the most important astronomers of all time . including ptolemy , who theorized about the movements of the planets . and zoroaster , who 's holding the celestial orb . we 're so far here from the medieval idea of the artist as a craftsman . here the artist is considered an intellectual on par with some the greatest thinkers in history , who can express these important ideas . so we have dozens of figures here without any sense of stiffness or repetition . raphael , like leonardo , in the last supper divides the figures into groups . each figure overlaps and moves easily between and amongst the others . my favorite two figures are the ones just behind euclid , one leaning against the wall with his leg crossed over the other who 's hurrying and writing some notes . the other leaning over and watching . there 's a wonderful sense of intimacy there . i think it 's a scene you could see walking along the hallway of any college or university . for all the free movement of the figures , the architecture itself is using a linear perspective in a rigorous way . you can follow the orthogonal either in the pavement , or in the cornices as they recede back . so the illusion of space here in incredible . look at the way that the decoration of the greek meander seems as if it goes back in space . what 's interesting though is if this architecture is harking back to any ancient tradition , it 's harking back to the roman tradition not to the greek 's who would never use barrel vaults in this way . nearby , bramante , raphael , michelangelo could see the baths of caracalla , or the basilica of manutius and constantine . there was roman architectural ruins all over the city that resembled what raphael has painted here . it 's so extraordinary that we 're celebrating here , the pantheon of great pagan thinkers . none of these men were christians . let 's take a quick look at the frescoes that 's opposite the school of athens known as the dispute . this frescoe represents theology , the study of the divine . figures here are divided between the heavenly and the earthly . close to the top we see god the father in the dome of heaven . below him , christ in this marvelous full-body halo , or mandorla , and he 's surrounded by the virgin mary on his right , and st. john the baptist on his left . just below , a dove against another gold disk , and this is the holy spirit , so all three together are the trinity . on either side of the dove are the four books of the gospels , matthew , mark , luke and john , that tell the story of the life of christ . on that wonderful bench of clouds sit prophets and saints . and we can actually recognize , for instance , moses holding the 10 commandments . and then another circle below contains the host , or the bread that is miraculously the body of christ during the mass . the bread functions as a link between heaven and earth . we can see how separated heaven and earth are in this fresco , and how important that link is . the figures along the bottom are popes , and bishops , and cardinals , and members of various religious orders . the fathers of the church , we can make out a portrait of dante , the great medieval poet . we have a sense of the figures on the bottom of the frescoe , coming to divine knowledge through the miracle of the host , and two figures on either end seem to be moving away from that divine knowledge . but there 's efforts being made to turn them around , to bring them back . so here , in the stanza della segnatura a room that functioned as the library for pope julius ii , a celebration of all aspects of human knowledge .
|
and we can see representations of classical sculpture in the niches on the left , that is on the platonic side . we see apollo , the god of the sun , the god of music , the god of poetry , things that would be appropriate to the platonic . in turn on the right , we see athena , the god of war and wisdom , who presumably is involved in the more practical affairs of man .
|
does her shield have the likeness of the nature god pan on it ?
|
we 're in the very crowded and not very large room called the stanza della segnatura that is not only dense with people , but it 's dense with imagery . we 're looking at frescoes by raphael . painted during the high renaissance at the same time that michelangelo was painting the sistine chapel ceiling just a few doors away . this room was originally a library , part of the papal apartments , that is the apartments where the pope lived . in order to imagine what this room would have looked like at the beginning of the 16th century , imagine away all of these people and imagine instead the lower walls lined with books . and also imagine quiet which is hard to do here , and an environment of learning where you could look up at what raphael painted here on the four walls which are the four branches of human knowledge , philosophy , having to do with things of this world . the philosophy at this time also meant what we know call the sciences . on the opposite wall theology , having to do with issues relating to god and the divine . and on the two other walls , poetry and justice . so these four areas of human knowledge symbolized by allegorical figures that we see on the ceiling , and it 's so clear that a few doors away is michelangelo because raphael is clearly looking at michelangelo 's figures on the ceiling of the sistine chapel especially the prophets and the sybils . what a moment in the high renaissance all commissioned thanks to pope julius ii . and think about what it means for theology to be presented equally with human knowledge . it is this extraordinarily liberal moment in church history . when humanist 's classical learning can be united with the teachings of the church . in the center of the school of athens , the frescoe that represents philosophy , we have the two great philosophers from antiquity in the center plato and aristotle surrounded by other great thinkers and philosophers and mathematicians from antiquity . virtually , every known great figure , but let 's start with the two in the center . we can tell plato from aristotle because plato is older . plato was , in fact , aristotle 's teacher , but also because he holds one of his own books , the timaeus . and aristotle holds his book , the ethics . both of those books represent the contrasting philosophies of these two men . plato was known for being interested in the ethereal , the theoretical , that which could not be seen , and , in fact , we see him pointing upward . this idea that the world of appearances is not the final truth , that there is a realm that is based on mathematics , on pure idea that is more true than the everyday world that we see . whereas , aristotle , his student , focused his attention on the observable , the actual , the physical . you 'll notice that his palm is down , and he seems to be saying , `` no , no , no , `` let 's pay attention to what is here . '' right , to what we can see and observe in the world . in fact , if you look at the colors that each of the figures wear , they refer to this division . plato wears red and purple , the purple referring to the ether what we would call the air , the red to fire , neither of which have weight . aristotle wears blue and brown that is the colors of earth and water which have gravity , which have weight . so the philosophers on either side of plato and aristotle continue this division . on the side of plato , we see philosophers concerned with issues of the ideal . for example , on the lower left we see pythagoras the great ancient mathematician who discovered laws of harmony in music , in mathematics . this idea that there is a reality that transcends the reality that we see . compare that to the lower right where we see euclid , the figure we associate with geometry . in fact , he seems to be drawing a geometric diagram for some very eager students . but he is interested in measure , that is the idea of the practical . euclid is modeled actually on a friend of raphael 's and that 's bramante the great architect asked by pope julius ii to provide a new model for a new saint peter 's . and in fact , appropriate to his reincarnation here as euclid , bramante 's design for saint peter 's was based on a perfect geometry of circles and squares . and is really visible in the architecture that raphael constructed for the school of athens . here we see an architecture that is very bramantian , but also very ancient roman . we have coffered barrel vaults , pilasters . this is a space that ennobles the figures that it contains . and we can see representations of classical sculpture in the niches on the left , that is on the platonic side . we see apollo , the god of the sun , the god of music , the god of poetry , things that would be appropriate to the platonic . in turn on the right , we see athena , the god of war and wisdom , who presumably is involved in the more practical affairs of man . all of this seems to me to be a place that is the opposite of the medieval where knowledge was something that was passed down by authority and one had to accept it . but here , on the walls of the papal apartments , we get this image of sharing knowledge and the history of the accumulation of knowledge all with figures who move beautifully who in their bodies represent a gracefulness that is a reflection of their inner wisdom and knowledge . you 'll notice that raphael has not placed any names within the painting . the only identifiers are perhaps the titles of the books that both plato and aristotle hold , and so we 're meant to understand who these figures are through their movement , through their dress . now , the artist has parted both groups to the left and the right so that the middle foreground is fairly empty . he does this , i think , for a couple of reasons . he wants the linear perspective at the bottom of the painting to balance the strong orthogonals at the top of the painting . he wants to make way for the advancement of plato and aristotle as they walk down the stairs , but we also have two figures in the foreground in the middle . we have diogenes , and most interestingly , we have the ancient philosopher , heraclitus , who seems to be writing and thinking quietly by himself . most of the other figures in this painting are engaged with others , but not this man . he seems to be lost in his own thoughts . well , and he is writing on a block of marble . in fact , his features are those of the great artist michelangelo known for his rather lonely and brooding personality . raphael has painted him here in the same pose as the prophet isaiah on the sistine ceiling although isaiah looks up , and here michelangelo 's heraclitus decidedly looks down . and so it 's so interesting that raphael is paying homage to michelangelo the great artist here personifying heraclitus , the philosopher who believed that all things were always in flux . that figure of heraclitus was actually added later . raphael finished the frescoe , added some wet plaster , and added in that figure . we should also note that raphael included himself here . that 's the young figure looking directly out at us in a black cap , and standing among some of the most important astronomers of all time . including ptolemy , who theorized about the movements of the planets . and zoroaster , who 's holding the celestial orb . we 're so far here from the medieval idea of the artist as a craftsman . here the artist is considered an intellectual on par with some the greatest thinkers in history , who can express these important ideas . so we have dozens of figures here without any sense of stiffness or repetition . raphael , like leonardo , in the last supper divides the figures into groups . each figure overlaps and moves easily between and amongst the others . my favorite two figures are the ones just behind euclid , one leaning against the wall with his leg crossed over the other who 's hurrying and writing some notes . the other leaning over and watching . there 's a wonderful sense of intimacy there . i think it 's a scene you could see walking along the hallway of any college or university . for all the free movement of the figures , the architecture itself is using a linear perspective in a rigorous way . you can follow the orthogonal either in the pavement , or in the cornices as they recede back . so the illusion of space here in incredible . look at the way that the decoration of the greek meander seems as if it goes back in space . what 's interesting though is if this architecture is harking back to any ancient tradition , it 's harking back to the roman tradition not to the greek 's who would never use barrel vaults in this way . nearby , bramante , raphael , michelangelo could see the baths of caracalla , or the basilica of manutius and constantine . there was roman architectural ruins all over the city that resembled what raphael has painted here . it 's so extraordinary that we 're celebrating here , the pantheon of great pagan thinkers . none of these men were christians . let 's take a quick look at the frescoes that 's opposite the school of athens known as the dispute . this frescoe represents theology , the study of the divine . figures here are divided between the heavenly and the earthly . close to the top we see god the father in the dome of heaven . below him , christ in this marvelous full-body halo , or mandorla , and he 's surrounded by the virgin mary on his right , and st. john the baptist on his left . just below , a dove against another gold disk , and this is the holy spirit , so all three together are the trinity . on either side of the dove are the four books of the gospels , matthew , mark , luke and john , that tell the story of the life of christ . on that wonderful bench of clouds sit prophets and saints . and we can actually recognize , for instance , moses holding the 10 commandments . and then another circle below contains the host , or the bread that is miraculously the body of christ during the mass . the bread functions as a link between heaven and earth . we can see how separated heaven and earth are in this fresco , and how important that link is . the figures along the bottom are popes , and bishops , and cardinals , and members of various religious orders . the fathers of the church , we can make out a portrait of dante , the great medieval poet . we have a sense of the figures on the bottom of the frescoe , coming to divine knowledge through the miracle of the host , and two figures on either end seem to be moving away from that divine knowledge . but there 's efforts being made to turn them around , to bring them back . so here , in the stanza della segnatura a room that functioned as the library for pope julius ii , a celebration of all aspects of human knowledge .
|
euclid is modeled actually on a friend of raphael 's and that 's bramante the great architect asked by pope julius ii to provide a new model for a new saint peter 's . and in fact , appropriate to his reincarnation here as euclid , bramante 's design for saint peter 's was based on a perfect geometry of circles and squares . and is really visible in the architecture that raphael constructed for the school of athens .
|
at 9.13 , how do we know that it is , in fact , john the baptist and not some other prophet or saint ?
|
we 're in the very crowded and not very large room called the stanza della segnatura that is not only dense with people , but it 's dense with imagery . we 're looking at frescoes by raphael . painted during the high renaissance at the same time that michelangelo was painting the sistine chapel ceiling just a few doors away . this room was originally a library , part of the papal apartments , that is the apartments where the pope lived . in order to imagine what this room would have looked like at the beginning of the 16th century , imagine away all of these people and imagine instead the lower walls lined with books . and also imagine quiet which is hard to do here , and an environment of learning where you could look up at what raphael painted here on the four walls which are the four branches of human knowledge , philosophy , having to do with things of this world . the philosophy at this time also meant what we know call the sciences . on the opposite wall theology , having to do with issues relating to god and the divine . and on the two other walls , poetry and justice . so these four areas of human knowledge symbolized by allegorical figures that we see on the ceiling , and it 's so clear that a few doors away is michelangelo because raphael is clearly looking at michelangelo 's figures on the ceiling of the sistine chapel especially the prophets and the sybils . what a moment in the high renaissance all commissioned thanks to pope julius ii . and think about what it means for theology to be presented equally with human knowledge . it is this extraordinarily liberal moment in church history . when humanist 's classical learning can be united with the teachings of the church . in the center of the school of athens , the frescoe that represents philosophy , we have the two great philosophers from antiquity in the center plato and aristotle surrounded by other great thinkers and philosophers and mathematicians from antiquity . virtually , every known great figure , but let 's start with the two in the center . we can tell plato from aristotle because plato is older . plato was , in fact , aristotle 's teacher , but also because he holds one of his own books , the timaeus . and aristotle holds his book , the ethics . both of those books represent the contrasting philosophies of these two men . plato was known for being interested in the ethereal , the theoretical , that which could not be seen , and , in fact , we see him pointing upward . this idea that the world of appearances is not the final truth , that there is a realm that is based on mathematics , on pure idea that is more true than the everyday world that we see . whereas , aristotle , his student , focused his attention on the observable , the actual , the physical . you 'll notice that his palm is down , and he seems to be saying , `` no , no , no , `` let 's pay attention to what is here . '' right , to what we can see and observe in the world . in fact , if you look at the colors that each of the figures wear , they refer to this division . plato wears red and purple , the purple referring to the ether what we would call the air , the red to fire , neither of which have weight . aristotle wears blue and brown that is the colors of earth and water which have gravity , which have weight . so the philosophers on either side of plato and aristotle continue this division . on the side of plato , we see philosophers concerned with issues of the ideal . for example , on the lower left we see pythagoras the great ancient mathematician who discovered laws of harmony in music , in mathematics . this idea that there is a reality that transcends the reality that we see . compare that to the lower right where we see euclid , the figure we associate with geometry . in fact , he seems to be drawing a geometric diagram for some very eager students . but he is interested in measure , that is the idea of the practical . euclid is modeled actually on a friend of raphael 's and that 's bramante the great architect asked by pope julius ii to provide a new model for a new saint peter 's . and in fact , appropriate to his reincarnation here as euclid , bramante 's design for saint peter 's was based on a perfect geometry of circles and squares . and is really visible in the architecture that raphael constructed for the school of athens . here we see an architecture that is very bramantian , but also very ancient roman . we have coffered barrel vaults , pilasters . this is a space that ennobles the figures that it contains . and we can see representations of classical sculpture in the niches on the left , that is on the platonic side . we see apollo , the god of the sun , the god of music , the god of poetry , things that would be appropriate to the platonic . in turn on the right , we see athena , the god of war and wisdom , who presumably is involved in the more practical affairs of man . all of this seems to me to be a place that is the opposite of the medieval where knowledge was something that was passed down by authority and one had to accept it . but here , on the walls of the papal apartments , we get this image of sharing knowledge and the history of the accumulation of knowledge all with figures who move beautifully who in their bodies represent a gracefulness that is a reflection of their inner wisdom and knowledge . you 'll notice that raphael has not placed any names within the painting . the only identifiers are perhaps the titles of the books that both plato and aristotle hold , and so we 're meant to understand who these figures are through their movement , through their dress . now , the artist has parted both groups to the left and the right so that the middle foreground is fairly empty . he does this , i think , for a couple of reasons . he wants the linear perspective at the bottom of the painting to balance the strong orthogonals at the top of the painting . he wants to make way for the advancement of plato and aristotle as they walk down the stairs , but we also have two figures in the foreground in the middle . we have diogenes , and most interestingly , we have the ancient philosopher , heraclitus , who seems to be writing and thinking quietly by himself . most of the other figures in this painting are engaged with others , but not this man . he seems to be lost in his own thoughts . well , and he is writing on a block of marble . in fact , his features are those of the great artist michelangelo known for his rather lonely and brooding personality . raphael has painted him here in the same pose as the prophet isaiah on the sistine ceiling although isaiah looks up , and here michelangelo 's heraclitus decidedly looks down . and so it 's so interesting that raphael is paying homage to michelangelo the great artist here personifying heraclitus , the philosopher who believed that all things were always in flux . that figure of heraclitus was actually added later . raphael finished the frescoe , added some wet plaster , and added in that figure . we should also note that raphael included himself here . that 's the young figure looking directly out at us in a black cap , and standing among some of the most important astronomers of all time . including ptolemy , who theorized about the movements of the planets . and zoroaster , who 's holding the celestial orb . we 're so far here from the medieval idea of the artist as a craftsman . here the artist is considered an intellectual on par with some the greatest thinkers in history , who can express these important ideas . so we have dozens of figures here without any sense of stiffness or repetition . raphael , like leonardo , in the last supper divides the figures into groups . each figure overlaps and moves easily between and amongst the others . my favorite two figures are the ones just behind euclid , one leaning against the wall with his leg crossed over the other who 's hurrying and writing some notes . the other leaning over and watching . there 's a wonderful sense of intimacy there . i think it 's a scene you could see walking along the hallway of any college or university . for all the free movement of the figures , the architecture itself is using a linear perspective in a rigorous way . you can follow the orthogonal either in the pavement , or in the cornices as they recede back . so the illusion of space here in incredible . look at the way that the decoration of the greek meander seems as if it goes back in space . what 's interesting though is if this architecture is harking back to any ancient tradition , it 's harking back to the roman tradition not to the greek 's who would never use barrel vaults in this way . nearby , bramante , raphael , michelangelo could see the baths of caracalla , or the basilica of manutius and constantine . there was roman architectural ruins all over the city that resembled what raphael has painted here . it 's so extraordinary that we 're celebrating here , the pantheon of great pagan thinkers . none of these men were christians . let 's take a quick look at the frescoes that 's opposite the school of athens known as the dispute . this frescoe represents theology , the study of the divine . figures here are divided between the heavenly and the earthly . close to the top we see god the father in the dome of heaven . below him , christ in this marvelous full-body halo , or mandorla , and he 's surrounded by the virgin mary on his right , and st. john the baptist on his left . just below , a dove against another gold disk , and this is the holy spirit , so all three together are the trinity . on either side of the dove are the four books of the gospels , matthew , mark , luke and john , that tell the story of the life of christ . on that wonderful bench of clouds sit prophets and saints . and we can actually recognize , for instance , moses holding the 10 commandments . and then another circle below contains the host , or the bread that is miraculously the body of christ during the mass . the bread functions as a link between heaven and earth . we can see how separated heaven and earth are in this fresco , and how important that link is . the figures along the bottom are popes , and bishops , and cardinals , and members of various religious orders . the fathers of the church , we can make out a portrait of dante , the great medieval poet . we have a sense of the figures on the bottom of the frescoe , coming to divine knowledge through the miracle of the host , and two figures on either end seem to be moving away from that divine knowledge . but there 's efforts being made to turn them around , to bring them back . so here , in the stanza della segnatura a room that functioned as the library for pope julius ii , a celebration of all aspects of human knowledge .
|
but here , on the walls of the papal apartments , we get this image of sharing knowledge and the history of the accumulation of knowledge all with figures who move beautifully who in their bodies represent a gracefulness that is a reflection of their inner wisdom and knowledge . you 'll notice that raphael has not placed any names within the painting . the only identifiers are perhaps the titles of the books that both plato and aristotle hold , and so we 're meant to understand who these figures are through their movement , through their dress .
|
there is a story that raphael put himself in the painting , but where is he ?
|
we 're in the very crowded and not very large room called the stanza della segnatura that is not only dense with people , but it 's dense with imagery . we 're looking at frescoes by raphael . painted during the high renaissance at the same time that michelangelo was painting the sistine chapel ceiling just a few doors away . this room was originally a library , part of the papal apartments , that is the apartments where the pope lived . in order to imagine what this room would have looked like at the beginning of the 16th century , imagine away all of these people and imagine instead the lower walls lined with books . and also imagine quiet which is hard to do here , and an environment of learning where you could look up at what raphael painted here on the four walls which are the four branches of human knowledge , philosophy , having to do with things of this world . the philosophy at this time also meant what we know call the sciences . on the opposite wall theology , having to do with issues relating to god and the divine . and on the two other walls , poetry and justice . so these four areas of human knowledge symbolized by allegorical figures that we see on the ceiling , and it 's so clear that a few doors away is michelangelo because raphael is clearly looking at michelangelo 's figures on the ceiling of the sistine chapel especially the prophets and the sybils . what a moment in the high renaissance all commissioned thanks to pope julius ii . and think about what it means for theology to be presented equally with human knowledge . it is this extraordinarily liberal moment in church history . when humanist 's classical learning can be united with the teachings of the church . in the center of the school of athens , the frescoe that represents philosophy , we have the two great philosophers from antiquity in the center plato and aristotle surrounded by other great thinkers and philosophers and mathematicians from antiquity . virtually , every known great figure , but let 's start with the two in the center . we can tell plato from aristotle because plato is older . plato was , in fact , aristotle 's teacher , but also because he holds one of his own books , the timaeus . and aristotle holds his book , the ethics . both of those books represent the contrasting philosophies of these two men . plato was known for being interested in the ethereal , the theoretical , that which could not be seen , and , in fact , we see him pointing upward . this idea that the world of appearances is not the final truth , that there is a realm that is based on mathematics , on pure idea that is more true than the everyday world that we see . whereas , aristotle , his student , focused his attention on the observable , the actual , the physical . you 'll notice that his palm is down , and he seems to be saying , `` no , no , no , `` let 's pay attention to what is here . '' right , to what we can see and observe in the world . in fact , if you look at the colors that each of the figures wear , they refer to this division . plato wears red and purple , the purple referring to the ether what we would call the air , the red to fire , neither of which have weight . aristotle wears blue and brown that is the colors of earth and water which have gravity , which have weight . so the philosophers on either side of plato and aristotle continue this division . on the side of plato , we see philosophers concerned with issues of the ideal . for example , on the lower left we see pythagoras the great ancient mathematician who discovered laws of harmony in music , in mathematics . this idea that there is a reality that transcends the reality that we see . compare that to the lower right where we see euclid , the figure we associate with geometry . in fact , he seems to be drawing a geometric diagram for some very eager students . but he is interested in measure , that is the idea of the practical . euclid is modeled actually on a friend of raphael 's and that 's bramante the great architect asked by pope julius ii to provide a new model for a new saint peter 's . and in fact , appropriate to his reincarnation here as euclid , bramante 's design for saint peter 's was based on a perfect geometry of circles and squares . and is really visible in the architecture that raphael constructed for the school of athens . here we see an architecture that is very bramantian , but also very ancient roman . we have coffered barrel vaults , pilasters . this is a space that ennobles the figures that it contains . and we can see representations of classical sculpture in the niches on the left , that is on the platonic side . we see apollo , the god of the sun , the god of music , the god of poetry , things that would be appropriate to the platonic . in turn on the right , we see athena , the god of war and wisdom , who presumably is involved in the more practical affairs of man . all of this seems to me to be a place that is the opposite of the medieval where knowledge was something that was passed down by authority and one had to accept it . but here , on the walls of the papal apartments , we get this image of sharing knowledge and the history of the accumulation of knowledge all with figures who move beautifully who in their bodies represent a gracefulness that is a reflection of their inner wisdom and knowledge . you 'll notice that raphael has not placed any names within the painting . the only identifiers are perhaps the titles of the books that both plato and aristotle hold , and so we 're meant to understand who these figures are through their movement , through their dress . now , the artist has parted both groups to the left and the right so that the middle foreground is fairly empty . he does this , i think , for a couple of reasons . he wants the linear perspective at the bottom of the painting to balance the strong orthogonals at the top of the painting . he wants to make way for the advancement of plato and aristotle as they walk down the stairs , but we also have two figures in the foreground in the middle . we have diogenes , and most interestingly , we have the ancient philosopher , heraclitus , who seems to be writing and thinking quietly by himself . most of the other figures in this painting are engaged with others , but not this man . he seems to be lost in his own thoughts . well , and he is writing on a block of marble . in fact , his features are those of the great artist michelangelo known for his rather lonely and brooding personality . raphael has painted him here in the same pose as the prophet isaiah on the sistine ceiling although isaiah looks up , and here michelangelo 's heraclitus decidedly looks down . and so it 's so interesting that raphael is paying homage to michelangelo the great artist here personifying heraclitus , the philosopher who believed that all things were always in flux . that figure of heraclitus was actually added later . raphael finished the frescoe , added some wet plaster , and added in that figure . we should also note that raphael included himself here . that 's the young figure looking directly out at us in a black cap , and standing among some of the most important astronomers of all time . including ptolemy , who theorized about the movements of the planets . and zoroaster , who 's holding the celestial orb . we 're so far here from the medieval idea of the artist as a craftsman . here the artist is considered an intellectual on par with some the greatest thinkers in history , who can express these important ideas . so we have dozens of figures here without any sense of stiffness or repetition . raphael , like leonardo , in the last supper divides the figures into groups . each figure overlaps and moves easily between and amongst the others . my favorite two figures are the ones just behind euclid , one leaning against the wall with his leg crossed over the other who 's hurrying and writing some notes . the other leaning over and watching . there 's a wonderful sense of intimacy there . i think it 's a scene you could see walking along the hallway of any college or university . for all the free movement of the figures , the architecture itself is using a linear perspective in a rigorous way . you can follow the orthogonal either in the pavement , or in the cornices as they recede back . so the illusion of space here in incredible . look at the way that the decoration of the greek meander seems as if it goes back in space . what 's interesting though is if this architecture is harking back to any ancient tradition , it 's harking back to the roman tradition not to the greek 's who would never use barrel vaults in this way . nearby , bramante , raphael , michelangelo could see the baths of caracalla , or the basilica of manutius and constantine . there was roman architectural ruins all over the city that resembled what raphael has painted here . it 's so extraordinary that we 're celebrating here , the pantheon of great pagan thinkers . none of these men were christians . let 's take a quick look at the frescoes that 's opposite the school of athens known as the dispute . this frescoe represents theology , the study of the divine . figures here are divided between the heavenly and the earthly . close to the top we see god the father in the dome of heaven . below him , christ in this marvelous full-body halo , or mandorla , and he 's surrounded by the virgin mary on his right , and st. john the baptist on his left . just below , a dove against another gold disk , and this is the holy spirit , so all three together are the trinity . on either side of the dove are the four books of the gospels , matthew , mark , luke and john , that tell the story of the life of christ . on that wonderful bench of clouds sit prophets and saints . and we can actually recognize , for instance , moses holding the 10 commandments . and then another circle below contains the host , or the bread that is miraculously the body of christ during the mass . the bread functions as a link between heaven and earth . we can see how separated heaven and earth are in this fresco , and how important that link is . the figures along the bottom are popes , and bishops , and cardinals , and members of various religious orders . the fathers of the church , we can make out a portrait of dante , the great medieval poet . we have a sense of the figures on the bottom of the frescoe , coming to divine knowledge through the miracle of the host , and two figures on either end seem to be moving away from that divine knowledge . but there 's efforts being made to turn them around , to bring them back . so here , in the stanza della segnatura a room that functioned as the library for pope julius ii , a celebration of all aspects of human knowledge .
|
and also imagine quiet which is hard to do here , and an environment of learning where you could look up at what raphael painted here on the four walls which are the four branches of human knowledge , philosophy , having to do with things of this world . the philosophy at this time also meant what we know call the sciences . on the opposite wall theology , having to do with issues relating to god and the divine .
|
the speaker throws out a lot of art terms i do n't know , could someone explain ?
|
we 're in the very crowded and not very large room called the stanza della segnatura that is not only dense with people , but it 's dense with imagery . we 're looking at frescoes by raphael . painted during the high renaissance at the same time that michelangelo was painting the sistine chapel ceiling just a few doors away . this room was originally a library , part of the papal apartments , that is the apartments where the pope lived . in order to imagine what this room would have looked like at the beginning of the 16th century , imagine away all of these people and imagine instead the lower walls lined with books . and also imagine quiet which is hard to do here , and an environment of learning where you could look up at what raphael painted here on the four walls which are the four branches of human knowledge , philosophy , having to do with things of this world . the philosophy at this time also meant what we know call the sciences . on the opposite wall theology , having to do with issues relating to god and the divine . and on the two other walls , poetry and justice . so these four areas of human knowledge symbolized by allegorical figures that we see on the ceiling , and it 's so clear that a few doors away is michelangelo because raphael is clearly looking at michelangelo 's figures on the ceiling of the sistine chapel especially the prophets and the sybils . what a moment in the high renaissance all commissioned thanks to pope julius ii . and think about what it means for theology to be presented equally with human knowledge . it is this extraordinarily liberal moment in church history . when humanist 's classical learning can be united with the teachings of the church . in the center of the school of athens , the frescoe that represents philosophy , we have the two great philosophers from antiquity in the center plato and aristotle surrounded by other great thinkers and philosophers and mathematicians from antiquity . virtually , every known great figure , but let 's start with the two in the center . we can tell plato from aristotle because plato is older . plato was , in fact , aristotle 's teacher , but also because he holds one of his own books , the timaeus . and aristotle holds his book , the ethics . both of those books represent the contrasting philosophies of these two men . plato was known for being interested in the ethereal , the theoretical , that which could not be seen , and , in fact , we see him pointing upward . this idea that the world of appearances is not the final truth , that there is a realm that is based on mathematics , on pure idea that is more true than the everyday world that we see . whereas , aristotle , his student , focused his attention on the observable , the actual , the physical . you 'll notice that his palm is down , and he seems to be saying , `` no , no , no , `` let 's pay attention to what is here . '' right , to what we can see and observe in the world . in fact , if you look at the colors that each of the figures wear , they refer to this division . plato wears red and purple , the purple referring to the ether what we would call the air , the red to fire , neither of which have weight . aristotle wears blue and brown that is the colors of earth and water which have gravity , which have weight . so the philosophers on either side of plato and aristotle continue this division . on the side of plato , we see philosophers concerned with issues of the ideal . for example , on the lower left we see pythagoras the great ancient mathematician who discovered laws of harmony in music , in mathematics . this idea that there is a reality that transcends the reality that we see . compare that to the lower right where we see euclid , the figure we associate with geometry . in fact , he seems to be drawing a geometric diagram for some very eager students . but he is interested in measure , that is the idea of the practical . euclid is modeled actually on a friend of raphael 's and that 's bramante the great architect asked by pope julius ii to provide a new model for a new saint peter 's . and in fact , appropriate to his reincarnation here as euclid , bramante 's design for saint peter 's was based on a perfect geometry of circles and squares . and is really visible in the architecture that raphael constructed for the school of athens . here we see an architecture that is very bramantian , but also very ancient roman . we have coffered barrel vaults , pilasters . this is a space that ennobles the figures that it contains . and we can see representations of classical sculpture in the niches on the left , that is on the platonic side . we see apollo , the god of the sun , the god of music , the god of poetry , things that would be appropriate to the platonic . in turn on the right , we see athena , the god of war and wisdom , who presumably is involved in the more practical affairs of man . all of this seems to me to be a place that is the opposite of the medieval where knowledge was something that was passed down by authority and one had to accept it . but here , on the walls of the papal apartments , we get this image of sharing knowledge and the history of the accumulation of knowledge all with figures who move beautifully who in their bodies represent a gracefulness that is a reflection of their inner wisdom and knowledge . you 'll notice that raphael has not placed any names within the painting . the only identifiers are perhaps the titles of the books that both plato and aristotle hold , and so we 're meant to understand who these figures are through their movement , through their dress . now , the artist has parted both groups to the left and the right so that the middle foreground is fairly empty . he does this , i think , for a couple of reasons . he wants the linear perspective at the bottom of the painting to balance the strong orthogonals at the top of the painting . he wants to make way for the advancement of plato and aristotle as they walk down the stairs , but we also have two figures in the foreground in the middle . we have diogenes , and most interestingly , we have the ancient philosopher , heraclitus , who seems to be writing and thinking quietly by himself . most of the other figures in this painting are engaged with others , but not this man . he seems to be lost in his own thoughts . well , and he is writing on a block of marble . in fact , his features are those of the great artist michelangelo known for his rather lonely and brooding personality . raphael has painted him here in the same pose as the prophet isaiah on the sistine ceiling although isaiah looks up , and here michelangelo 's heraclitus decidedly looks down . and so it 's so interesting that raphael is paying homage to michelangelo the great artist here personifying heraclitus , the philosopher who believed that all things were always in flux . that figure of heraclitus was actually added later . raphael finished the frescoe , added some wet plaster , and added in that figure . we should also note that raphael included himself here . that 's the young figure looking directly out at us in a black cap , and standing among some of the most important astronomers of all time . including ptolemy , who theorized about the movements of the planets . and zoroaster , who 's holding the celestial orb . we 're so far here from the medieval idea of the artist as a craftsman . here the artist is considered an intellectual on par with some the greatest thinkers in history , who can express these important ideas . so we have dozens of figures here without any sense of stiffness or repetition . raphael , like leonardo , in the last supper divides the figures into groups . each figure overlaps and moves easily between and amongst the others . my favorite two figures are the ones just behind euclid , one leaning against the wall with his leg crossed over the other who 's hurrying and writing some notes . the other leaning over and watching . there 's a wonderful sense of intimacy there . i think it 's a scene you could see walking along the hallway of any college or university . for all the free movement of the figures , the architecture itself is using a linear perspective in a rigorous way . you can follow the orthogonal either in the pavement , or in the cornices as they recede back . so the illusion of space here in incredible . look at the way that the decoration of the greek meander seems as if it goes back in space . what 's interesting though is if this architecture is harking back to any ancient tradition , it 's harking back to the roman tradition not to the greek 's who would never use barrel vaults in this way . nearby , bramante , raphael , michelangelo could see the baths of caracalla , or the basilica of manutius and constantine . there was roman architectural ruins all over the city that resembled what raphael has painted here . it 's so extraordinary that we 're celebrating here , the pantheon of great pagan thinkers . none of these men were christians . let 's take a quick look at the frescoes that 's opposite the school of athens known as the dispute . this frescoe represents theology , the study of the divine . figures here are divided between the heavenly and the earthly . close to the top we see god the father in the dome of heaven . below him , christ in this marvelous full-body halo , or mandorla , and he 's surrounded by the virgin mary on his right , and st. john the baptist on his left . just below , a dove against another gold disk , and this is the holy spirit , so all three together are the trinity . on either side of the dove are the four books of the gospels , matthew , mark , luke and john , that tell the story of the life of christ . on that wonderful bench of clouds sit prophets and saints . and we can actually recognize , for instance , moses holding the 10 commandments . and then another circle below contains the host , or the bread that is miraculously the body of christ during the mass . the bread functions as a link between heaven and earth . we can see how separated heaven and earth are in this fresco , and how important that link is . the figures along the bottom are popes , and bishops , and cardinals , and members of various religious orders . the fathers of the church , we can make out a portrait of dante , the great medieval poet . we have a sense of the figures on the bottom of the frescoe , coming to divine knowledge through the miracle of the host , and two figures on either end seem to be moving away from that divine knowledge . but there 's efforts being made to turn them around , to bring them back . so here , in the stanza della segnatura a room that functioned as the library for pope julius ii , a celebration of all aspects of human knowledge .
|
virtually , every known great figure , but let 's start with the two in the center . we can tell plato from aristotle because plato is older . plato was , in fact , aristotle 's teacher , but also because he holds one of his own books , the timaeus .
|
why did raphael place him on team plato ?
|
we 're in the very crowded and not very large room called the stanza della segnatura that is not only dense with people , but it 's dense with imagery . we 're looking at frescoes by raphael . painted during the high renaissance at the same time that michelangelo was painting the sistine chapel ceiling just a few doors away . this room was originally a library , part of the papal apartments , that is the apartments where the pope lived . in order to imagine what this room would have looked like at the beginning of the 16th century , imagine away all of these people and imagine instead the lower walls lined with books . and also imagine quiet which is hard to do here , and an environment of learning where you could look up at what raphael painted here on the four walls which are the four branches of human knowledge , philosophy , having to do with things of this world . the philosophy at this time also meant what we know call the sciences . on the opposite wall theology , having to do with issues relating to god and the divine . and on the two other walls , poetry and justice . so these four areas of human knowledge symbolized by allegorical figures that we see on the ceiling , and it 's so clear that a few doors away is michelangelo because raphael is clearly looking at michelangelo 's figures on the ceiling of the sistine chapel especially the prophets and the sybils . what a moment in the high renaissance all commissioned thanks to pope julius ii . and think about what it means for theology to be presented equally with human knowledge . it is this extraordinarily liberal moment in church history . when humanist 's classical learning can be united with the teachings of the church . in the center of the school of athens , the frescoe that represents philosophy , we have the two great philosophers from antiquity in the center plato and aristotle surrounded by other great thinkers and philosophers and mathematicians from antiquity . virtually , every known great figure , but let 's start with the two in the center . we can tell plato from aristotle because plato is older . plato was , in fact , aristotle 's teacher , but also because he holds one of his own books , the timaeus . and aristotle holds his book , the ethics . both of those books represent the contrasting philosophies of these two men . plato was known for being interested in the ethereal , the theoretical , that which could not be seen , and , in fact , we see him pointing upward . this idea that the world of appearances is not the final truth , that there is a realm that is based on mathematics , on pure idea that is more true than the everyday world that we see . whereas , aristotle , his student , focused his attention on the observable , the actual , the physical . you 'll notice that his palm is down , and he seems to be saying , `` no , no , no , `` let 's pay attention to what is here . '' right , to what we can see and observe in the world . in fact , if you look at the colors that each of the figures wear , they refer to this division . plato wears red and purple , the purple referring to the ether what we would call the air , the red to fire , neither of which have weight . aristotle wears blue and brown that is the colors of earth and water which have gravity , which have weight . so the philosophers on either side of plato and aristotle continue this division . on the side of plato , we see philosophers concerned with issues of the ideal . for example , on the lower left we see pythagoras the great ancient mathematician who discovered laws of harmony in music , in mathematics . this idea that there is a reality that transcends the reality that we see . compare that to the lower right where we see euclid , the figure we associate with geometry . in fact , he seems to be drawing a geometric diagram for some very eager students . but he is interested in measure , that is the idea of the practical . euclid is modeled actually on a friend of raphael 's and that 's bramante the great architect asked by pope julius ii to provide a new model for a new saint peter 's . and in fact , appropriate to his reincarnation here as euclid , bramante 's design for saint peter 's was based on a perfect geometry of circles and squares . and is really visible in the architecture that raphael constructed for the school of athens . here we see an architecture that is very bramantian , but also very ancient roman . we have coffered barrel vaults , pilasters . this is a space that ennobles the figures that it contains . and we can see representations of classical sculpture in the niches on the left , that is on the platonic side . we see apollo , the god of the sun , the god of music , the god of poetry , things that would be appropriate to the platonic . in turn on the right , we see athena , the god of war and wisdom , who presumably is involved in the more practical affairs of man . all of this seems to me to be a place that is the opposite of the medieval where knowledge was something that was passed down by authority and one had to accept it . but here , on the walls of the papal apartments , we get this image of sharing knowledge and the history of the accumulation of knowledge all with figures who move beautifully who in their bodies represent a gracefulness that is a reflection of their inner wisdom and knowledge . you 'll notice that raphael has not placed any names within the painting . the only identifiers are perhaps the titles of the books that both plato and aristotle hold , and so we 're meant to understand who these figures are through their movement , through their dress . now , the artist has parted both groups to the left and the right so that the middle foreground is fairly empty . he does this , i think , for a couple of reasons . he wants the linear perspective at the bottom of the painting to balance the strong orthogonals at the top of the painting . he wants to make way for the advancement of plato and aristotle as they walk down the stairs , but we also have two figures in the foreground in the middle . we have diogenes , and most interestingly , we have the ancient philosopher , heraclitus , who seems to be writing and thinking quietly by himself . most of the other figures in this painting are engaged with others , but not this man . he seems to be lost in his own thoughts . well , and he is writing on a block of marble . in fact , his features are those of the great artist michelangelo known for his rather lonely and brooding personality . raphael has painted him here in the same pose as the prophet isaiah on the sistine ceiling although isaiah looks up , and here michelangelo 's heraclitus decidedly looks down . and so it 's so interesting that raphael is paying homage to michelangelo the great artist here personifying heraclitus , the philosopher who believed that all things were always in flux . that figure of heraclitus was actually added later . raphael finished the frescoe , added some wet plaster , and added in that figure . we should also note that raphael included himself here . that 's the young figure looking directly out at us in a black cap , and standing among some of the most important astronomers of all time . including ptolemy , who theorized about the movements of the planets . and zoroaster , who 's holding the celestial orb . we 're so far here from the medieval idea of the artist as a craftsman . here the artist is considered an intellectual on par with some the greatest thinkers in history , who can express these important ideas . so we have dozens of figures here without any sense of stiffness or repetition . raphael , like leonardo , in the last supper divides the figures into groups . each figure overlaps and moves easily between and amongst the others . my favorite two figures are the ones just behind euclid , one leaning against the wall with his leg crossed over the other who 's hurrying and writing some notes . the other leaning over and watching . there 's a wonderful sense of intimacy there . i think it 's a scene you could see walking along the hallway of any college or university . for all the free movement of the figures , the architecture itself is using a linear perspective in a rigorous way . you can follow the orthogonal either in the pavement , or in the cornices as they recede back . so the illusion of space here in incredible . look at the way that the decoration of the greek meander seems as if it goes back in space . what 's interesting though is if this architecture is harking back to any ancient tradition , it 's harking back to the roman tradition not to the greek 's who would never use barrel vaults in this way . nearby , bramante , raphael , michelangelo could see the baths of caracalla , or the basilica of manutius and constantine . there was roman architectural ruins all over the city that resembled what raphael has painted here . it 's so extraordinary that we 're celebrating here , the pantheon of great pagan thinkers . none of these men were christians . let 's take a quick look at the frescoes that 's opposite the school of athens known as the dispute . this frescoe represents theology , the study of the divine . figures here are divided between the heavenly and the earthly . close to the top we see god the father in the dome of heaven . below him , christ in this marvelous full-body halo , or mandorla , and he 's surrounded by the virgin mary on his right , and st. john the baptist on his left . just below , a dove against another gold disk , and this is the holy spirit , so all three together are the trinity . on either side of the dove are the four books of the gospels , matthew , mark , luke and john , that tell the story of the life of christ . on that wonderful bench of clouds sit prophets and saints . and we can actually recognize , for instance , moses holding the 10 commandments . and then another circle below contains the host , or the bread that is miraculously the body of christ during the mass . the bread functions as a link between heaven and earth . we can see how separated heaven and earth are in this fresco , and how important that link is . the figures along the bottom are popes , and bishops , and cardinals , and members of various religious orders . the fathers of the church , we can make out a portrait of dante , the great medieval poet . we have a sense of the figures on the bottom of the frescoe , coming to divine knowledge through the miracle of the host , and two figures on either end seem to be moving away from that divine knowledge . but there 's efforts being made to turn them around , to bring them back . so here , in the stanza della segnatura a room that functioned as the library for pope julius ii , a celebration of all aspects of human knowledge .
|
what a moment in the high renaissance all commissioned thanks to pope julius ii . and think about what it means for theology to be presented equally with human knowledge . it is this extraordinarily liberal moment in church history .
|
quick question- did all the later popes like this equality of the human knowledge and theology or did some oppose it ?
|
we 're in the very crowded and not very large room called the stanza della segnatura that is not only dense with people , but it 's dense with imagery . we 're looking at frescoes by raphael . painted during the high renaissance at the same time that michelangelo was painting the sistine chapel ceiling just a few doors away . this room was originally a library , part of the papal apartments , that is the apartments where the pope lived . in order to imagine what this room would have looked like at the beginning of the 16th century , imagine away all of these people and imagine instead the lower walls lined with books . and also imagine quiet which is hard to do here , and an environment of learning where you could look up at what raphael painted here on the four walls which are the four branches of human knowledge , philosophy , having to do with things of this world . the philosophy at this time also meant what we know call the sciences . on the opposite wall theology , having to do with issues relating to god and the divine . and on the two other walls , poetry and justice . so these four areas of human knowledge symbolized by allegorical figures that we see on the ceiling , and it 's so clear that a few doors away is michelangelo because raphael is clearly looking at michelangelo 's figures on the ceiling of the sistine chapel especially the prophets and the sybils . what a moment in the high renaissance all commissioned thanks to pope julius ii . and think about what it means for theology to be presented equally with human knowledge . it is this extraordinarily liberal moment in church history . when humanist 's classical learning can be united with the teachings of the church . in the center of the school of athens , the frescoe that represents philosophy , we have the two great philosophers from antiquity in the center plato and aristotle surrounded by other great thinkers and philosophers and mathematicians from antiquity . virtually , every known great figure , but let 's start with the two in the center . we can tell plato from aristotle because plato is older . plato was , in fact , aristotle 's teacher , but also because he holds one of his own books , the timaeus . and aristotle holds his book , the ethics . both of those books represent the contrasting philosophies of these two men . plato was known for being interested in the ethereal , the theoretical , that which could not be seen , and , in fact , we see him pointing upward . this idea that the world of appearances is not the final truth , that there is a realm that is based on mathematics , on pure idea that is more true than the everyday world that we see . whereas , aristotle , his student , focused his attention on the observable , the actual , the physical . you 'll notice that his palm is down , and he seems to be saying , `` no , no , no , `` let 's pay attention to what is here . '' right , to what we can see and observe in the world . in fact , if you look at the colors that each of the figures wear , they refer to this division . plato wears red and purple , the purple referring to the ether what we would call the air , the red to fire , neither of which have weight . aristotle wears blue and brown that is the colors of earth and water which have gravity , which have weight . so the philosophers on either side of plato and aristotle continue this division . on the side of plato , we see philosophers concerned with issues of the ideal . for example , on the lower left we see pythagoras the great ancient mathematician who discovered laws of harmony in music , in mathematics . this idea that there is a reality that transcends the reality that we see . compare that to the lower right where we see euclid , the figure we associate with geometry . in fact , he seems to be drawing a geometric diagram for some very eager students . but he is interested in measure , that is the idea of the practical . euclid is modeled actually on a friend of raphael 's and that 's bramante the great architect asked by pope julius ii to provide a new model for a new saint peter 's . and in fact , appropriate to his reincarnation here as euclid , bramante 's design for saint peter 's was based on a perfect geometry of circles and squares . and is really visible in the architecture that raphael constructed for the school of athens . here we see an architecture that is very bramantian , but also very ancient roman . we have coffered barrel vaults , pilasters . this is a space that ennobles the figures that it contains . and we can see representations of classical sculpture in the niches on the left , that is on the platonic side . we see apollo , the god of the sun , the god of music , the god of poetry , things that would be appropriate to the platonic . in turn on the right , we see athena , the god of war and wisdom , who presumably is involved in the more practical affairs of man . all of this seems to me to be a place that is the opposite of the medieval where knowledge was something that was passed down by authority and one had to accept it . but here , on the walls of the papal apartments , we get this image of sharing knowledge and the history of the accumulation of knowledge all with figures who move beautifully who in their bodies represent a gracefulness that is a reflection of their inner wisdom and knowledge . you 'll notice that raphael has not placed any names within the painting . the only identifiers are perhaps the titles of the books that both plato and aristotle hold , and so we 're meant to understand who these figures are through their movement , through their dress . now , the artist has parted both groups to the left and the right so that the middle foreground is fairly empty . he does this , i think , for a couple of reasons . he wants the linear perspective at the bottom of the painting to balance the strong orthogonals at the top of the painting . he wants to make way for the advancement of plato and aristotle as they walk down the stairs , but we also have two figures in the foreground in the middle . we have diogenes , and most interestingly , we have the ancient philosopher , heraclitus , who seems to be writing and thinking quietly by himself . most of the other figures in this painting are engaged with others , but not this man . he seems to be lost in his own thoughts . well , and he is writing on a block of marble . in fact , his features are those of the great artist michelangelo known for his rather lonely and brooding personality . raphael has painted him here in the same pose as the prophet isaiah on the sistine ceiling although isaiah looks up , and here michelangelo 's heraclitus decidedly looks down . and so it 's so interesting that raphael is paying homage to michelangelo the great artist here personifying heraclitus , the philosopher who believed that all things were always in flux . that figure of heraclitus was actually added later . raphael finished the frescoe , added some wet plaster , and added in that figure . we should also note that raphael included himself here . that 's the young figure looking directly out at us in a black cap , and standing among some of the most important astronomers of all time . including ptolemy , who theorized about the movements of the planets . and zoroaster , who 's holding the celestial orb . we 're so far here from the medieval idea of the artist as a craftsman . here the artist is considered an intellectual on par with some the greatest thinkers in history , who can express these important ideas . so we have dozens of figures here without any sense of stiffness or repetition . raphael , like leonardo , in the last supper divides the figures into groups . each figure overlaps and moves easily between and amongst the others . my favorite two figures are the ones just behind euclid , one leaning against the wall with his leg crossed over the other who 's hurrying and writing some notes . the other leaning over and watching . there 's a wonderful sense of intimacy there . i think it 's a scene you could see walking along the hallway of any college or university . for all the free movement of the figures , the architecture itself is using a linear perspective in a rigorous way . you can follow the orthogonal either in the pavement , or in the cornices as they recede back . so the illusion of space here in incredible . look at the way that the decoration of the greek meander seems as if it goes back in space . what 's interesting though is if this architecture is harking back to any ancient tradition , it 's harking back to the roman tradition not to the greek 's who would never use barrel vaults in this way . nearby , bramante , raphael , michelangelo could see the baths of caracalla , or the basilica of manutius and constantine . there was roman architectural ruins all over the city that resembled what raphael has painted here . it 's so extraordinary that we 're celebrating here , the pantheon of great pagan thinkers . none of these men were christians . let 's take a quick look at the frescoes that 's opposite the school of athens known as the dispute . this frescoe represents theology , the study of the divine . figures here are divided between the heavenly and the earthly . close to the top we see god the father in the dome of heaven . below him , christ in this marvelous full-body halo , or mandorla , and he 's surrounded by the virgin mary on his right , and st. john the baptist on his left . just below , a dove against another gold disk , and this is the holy spirit , so all three together are the trinity . on either side of the dove are the four books of the gospels , matthew , mark , luke and john , that tell the story of the life of christ . on that wonderful bench of clouds sit prophets and saints . and we can actually recognize , for instance , moses holding the 10 commandments . and then another circle below contains the host , or the bread that is miraculously the body of christ during the mass . the bread functions as a link between heaven and earth . we can see how separated heaven and earth are in this fresco , and how important that link is . the figures along the bottom are popes , and bishops , and cardinals , and members of various religious orders . the fathers of the church , we can make out a portrait of dante , the great medieval poet . we have a sense of the figures on the bottom of the frescoe , coming to divine knowledge through the miracle of the host , and two figures on either end seem to be moving away from that divine knowledge . but there 's efforts being made to turn them around , to bring them back . so here , in the stanza della segnatura a room that functioned as the library for pope julius ii , a celebration of all aspects of human knowledge .
|
so we have dozens of figures here without any sense of stiffness or repetition . raphael , like leonardo , in the last supper divides the figures into groups . each figure overlaps and moves easily between and amongst the others .
|
when was the site last updated ?
|
we 're in the very crowded and not very large room called the stanza della segnatura that is not only dense with people , but it 's dense with imagery . we 're looking at frescoes by raphael . painted during the high renaissance at the same time that michelangelo was painting the sistine chapel ceiling just a few doors away . this room was originally a library , part of the papal apartments , that is the apartments where the pope lived . in order to imagine what this room would have looked like at the beginning of the 16th century , imagine away all of these people and imagine instead the lower walls lined with books . and also imagine quiet which is hard to do here , and an environment of learning where you could look up at what raphael painted here on the four walls which are the four branches of human knowledge , philosophy , having to do with things of this world . the philosophy at this time also meant what we know call the sciences . on the opposite wall theology , having to do with issues relating to god and the divine . and on the two other walls , poetry and justice . so these four areas of human knowledge symbolized by allegorical figures that we see on the ceiling , and it 's so clear that a few doors away is michelangelo because raphael is clearly looking at michelangelo 's figures on the ceiling of the sistine chapel especially the prophets and the sybils . what a moment in the high renaissance all commissioned thanks to pope julius ii . and think about what it means for theology to be presented equally with human knowledge . it is this extraordinarily liberal moment in church history . when humanist 's classical learning can be united with the teachings of the church . in the center of the school of athens , the frescoe that represents philosophy , we have the two great philosophers from antiquity in the center plato and aristotle surrounded by other great thinkers and philosophers and mathematicians from antiquity . virtually , every known great figure , but let 's start with the two in the center . we can tell plato from aristotle because plato is older . plato was , in fact , aristotle 's teacher , but also because he holds one of his own books , the timaeus . and aristotle holds his book , the ethics . both of those books represent the contrasting philosophies of these two men . plato was known for being interested in the ethereal , the theoretical , that which could not be seen , and , in fact , we see him pointing upward . this idea that the world of appearances is not the final truth , that there is a realm that is based on mathematics , on pure idea that is more true than the everyday world that we see . whereas , aristotle , his student , focused his attention on the observable , the actual , the physical . you 'll notice that his palm is down , and he seems to be saying , `` no , no , no , `` let 's pay attention to what is here . '' right , to what we can see and observe in the world . in fact , if you look at the colors that each of the figures wear , they refer to this division . plato wears red and purple , the purple referring to the ether what we would call the air , the red to fire , neither of which have weight . aristotle wears blue and brown that is the colors of earth and water which have gravity , which have weight . so the philosophers on either side of plato and aristotle continue this division . on the side of plato , we see philosophers concerned with issues of the ideal . for example , on the lower left we see pythagoras the great ancient mathematician who discovered laws of harmony in music , in mathematics . this idea that there is a reality that transcends the reality that we see . compare that to the lower right where we see euclid , the figure we associate with geometry . in fact , he seems to be drawing a geometric diagram for some very eager students . but he is interested in measure , that is the idea of the practical . euclid is modeled actually on a friend of raphael 's and that 's bramante the great architect asked by pope julius ii to provide a new model for a new saint peter 's . and in fact , appropriate to his reincarnation here as euclid , bramante 's design for saint peter 's was based on a perfect geometry of circles and squares . and is really visible in the architecture that raphael constructed for the school of athens . here we see an architecture that is very bramantian , but also very ancient roman . we have coffered barrel vaults , pilasters . this is a space that ennobles the figures that it contains . and we can see representations of classical sculpture in the niches on the left , that is on the platonic side . we see apollo , the god of the sun , the god of music , the god of poetry , things that would be appropriate to the platonic . in turn on the right , we see athena , the god of war and wisdom , who presumably is involved in the more practical affairs of man . all of this seems to me to be a place that is the opposite of the medieval where knowledge was something that was passed down by authority and one had to accept it . but here , on the walls of the papal apartments , we get this image of sharing knowledge and the history of the accumulation of knowledge all with figures who move beautifully who in their bodies represent a gracefulness that is a reflection of their inner wisdom and knowledge . you 'll notice that raphael has not placed any names within the painting . the only identifiers are perhaps the titles of the books that both plato and aristotle hold , and so we 're meant to understand who these figures are through their movement , through their dress . now , the artist has parted both groups to the left and the right so that the middle foreground is fairly empty . he does this , i think , for a couple of reasons . he wants the linear perspective at the bottom of the painting to balance the strong orthogonals at the top of the painting . he wants to make way for the advancement of plato and aristotle as they walk down the stairs , but we also have two figures in the foreground in the middle . we have diogenes , and most interestingly , we have the ancient philosopher , heraclitus , who seems to be writing and thinking quietly by himself . most of the other figures in this painting are engaged with others , but not this man . he seems to be lost in his own thoughts . well , and he is writing on a block of marble . in fact , his features are those of the great artist michelangelo known for his rather lonely and brooding personality . raphael has painted him here in the same pose as the prophet isaiah on the sistine ceiling although isaiah looks up , and here michelangelo 's heraclitus decidedly looks down . and so it 's so interesting that raphael is paying homage to michelangelo the great artist here personifying heraclitus , the philosopher who believed that all things were always in flux . that figure of heraclitus was actually added later . raphael finished the frescoe , added some wet plaster , and added in that figure . we should also note that raphael included himself here . that 's the young figure looking directly out at us in a black cap , and standing among some of the most important astronomers of all time . including ptolemy , who theorized about the movements of the planets . and zoroaster , who 's holding the celestial orb . we 're so far here from the medieval idea of the artist as a craftsman . here the artist is considered an intellectual on par with some the greatest thinkers in history , who can express these important ideas . so we have dozens of figures here without any sense of stiffness or repetition . raphael , like leonardo , in the last supper divides the figures into groups . each figure overlaps and moves easily between and amongst the others . my favorite two figures are the ones just behind euclid , one leaning against the wall with his leg crossed over the other who 's hurrying and writing some notes . the other leaning over and watching . there 's a wonderful sense of intimacy there . i think it 's a scene you could see walking along the hallway of any college or university . for all the free movement of the figures , the architecture itself is using a linear perspective in a rigorous way . you can follow the orthogonal either in the pavement , or in the cornices as they recede back . so the illusion of space here in incredible . look at the way that the decoration of the greek meander seems as if it goes back in space . what 's interesting though is if this architecture is harking back to any ancient tradition , it 's harking back to the roman tradition not to the greek 's who would never use barrel vaults in this way . nearby , bramante , raphael , michelangelo could see the baths of caracalla , or the basilica of manutius and constantine . there was roman architectural ruins all over the city that resembled what raphael has painted here . it 's so extraordinary that we 're celebrating here , the pantheon of great pagan thinkers . none of these men were christians . let 's take a quick look at the frescoes that 's opposite the school of athens known as the dispute . this frescoe represents theology , the study of the divine . figures here are divided between the heavenly and the earthly . close to the top we see god the father in the dome of heaven . below him , christ in this marvelous full-body halo , or mandorla , and he 's surrounded by the virgin mary on his right , and st. john the baptist on his left . just below , a dove against another gold disk , and this is the holy spirit , so all three together are the trinity . on either side of the dove are the four books of the gospels , matthew , mark , luke and john , that tell the story of the life of christ . on that wonderful bench of clouds sit prophets and saints . and we can actually recognize , for instance , moses holding the 10 commandments . and then another circle below contains the host , or the bread that is miraculously the body of christ during the mass . the bread functions as a link between heaven and earth . we can see how separated heaven and earth are in this fresco , and how important that link is . the figures along the bottom are popes , and bishops , and cardinals , and members of various religious orders . the fathers of the church , we can make out a portrait of dante , the great medieval poet . we have a sense of the figures on the bottom of the frescoe , coming to divine knowledge through the miracle of the host , and two figures on either end seem to be moving away from that divine knowledge . but there 's efforts being made to turn them around , to bring them back . so here , in the stanza della segnatura a room that functioned as the library for pope julius ii , a celebration of all aspects of human knowledge .
|
and in fact , appropriate to his reincarnation here as euclid , bramante 's design for saint peter 's was based on a perfect geometry of circles and squares . and is really visible in the architecture that raphael constructed for the school of athens . here we see an architecture that is very bramantian , but also very ancient roman .
|
why is it entitle `` the school of athens '' ?
|
we 're in the very crowded and not very large room called the stanza della segnatura that is not only dense with people , but it 's dense with imagery . we 're looking at frescoes by raphael . painted during the high renaissance at the same time that michelangelo was painting the sistine chapel ceiling just a few doors away . this room was originally a library , part of the papal apartments , that is the apartments where the pope lived . in order to imagine what this room would have looked like at the beginning of the 16th century , imagine away all of these people and imagine instead the lower walls lined with books . and also imagine quiet which is hard to do here , and an environment of learning where you could look up at what raphael painted here on the four walls which are the four branches of human knowledge , philosophy , having to do with things of this world . the philosophy at this time also meant what we know call the sciences . on the opposite wall theology , having to do with issues relating to god and the divine . and on the two other walls , poetry and justice . so these four areas of human knowledge symbolized by allegorical figures that we see on the ceiling , and it 's so clear that a few doors away is michelangelo because raphael is clearly looking at michelangelo 's figures on the ceiling of the sistine chapel especially the prophets and the sybils . what a moment in the high renaissance all commissioned thanks to pope julius ii . and think about what it means for theology to be presented equally with human knowledge . it is this extraordinarily liberal moment in church history . when humanist 's classical learning can be united with the teachings of the church . in the center of the school of athens , the frescoe that represents philosophy , we have the two great philosophers from antiquity in the center plato and aristotle surrounded by other great thinkers and philosophers and mathematicians from antiquity . virtually , every known great figure , but let 's start with the two in the center . we can tell plato from aristotle because plato is older . plato was , in fact , aristotle 's teacher , but also because he holds one of his own books , the timaeus . and aristotle holds his book , the ethics . both of those books represent the contrasting philosophies of these two men . plato was known for being interested in the ethereal , the theoretical , that which could not be seen , and , in fact , we see him pointing upward . this idea that the world of appearances is not the final truth , that there is a realm that is based on mathematics , on pure idea that is more true than the everyday world that we see . whereas , aristotle , his student , focused his attention on the observable , the actual , the physical . you 'll notice that his palm is down , and he seems to be saying , `` no , no , no , `` let 's pay attention to what is here . '' right , to what we can see and observe in the world . in fact , if you look at the colors that each of the figures wear , they refer to this division . plato wears red and purple , the purple referring to the ether what we would call the air , the red to fire , neither of which have weight . aristotle wears blue and brown that is the colors of earth and water which have gravity , which have weight . so the philosophers on either side of plato and aristotle continue this division . on the side of plato , we see philosophers concerned with issues of the ideal . for example , on the lower left we see pythagoras the great ancient mathematician who discovered laws of harmony in music , in mathematics . this idea that there is a reality that transcends the reality that we see . compare that to the lower right where we see euclid , the figure we associate with geometry . in fact , he seems to be drawing a geometric diagram for some very eager students . but he is interested in measure , that is the idea of the practical . euclid is modeled actually on a friend of raphael 's and that 's bramante the great architect asked by pope julius ii to provide a new model for a new saint peter 's . and in fact , appropriate to his reincarnation here as euclid , bramante 's design for saint peter 's was based on a perfect geometry of circles and squares . and is really visible in the architecture that raphael constructed for the school of athens . here we see an architecture that is very bramantian , but also very ancient roman . we have coffered barrel vaults , pilasters . this is a space that ennobles the figures that it contains . and we can see representations of classical sculpture in the niches on the left , that is on the platonic side . we see apollo , the god of the sun , the god of music , the god of poetry , things that would be appropriate to the platonic . in turn on the right , we see athena , the god of war and wisdom , who presumably is involved in the more practical affairs of man . all of this seems to me to be a place that is the opposite of the medieval where knowledge was something that was passed down by authority and one had to accept it . but here , on the walls of the papal apartments , we get this image of sharing knowledge and the history of the accumulation of knowledge all with figures who move beautifully who in their bodies represent a gracefulness that is a reflection of their inner wisdom and knowledge . you 'll notice that raphael has not placed any names within the painting . the only identifiers are perhaps the titles of the books that both plato and aristotle hold , and so we 're meant to understand who these figures are through their movement , through their dress . now , the artist has parted both groups to the left and the right so that the middle foreground is fairly empty . he does this , i think , for a couple of reasons . he wants the linear perspective at the bottom of the painting to balance the strong orthogonals at the top of the painting . he wants to make way for the advancement of plato and aristotle as they walk down the stairs , but we also have two figures in the foreground in the middle . we have diogenes , and most interestingly , we have the ancient philosopher , heraclitus , who seems to be writing and thinking quietly by himself . most of the other figures in this painting are engaged with others , but not this man . he seems to be lost in his own thoughts . well , and he is writing on a block of marble . in fact , his features are those of the great artist michelangelo known for his rather lonely and brooding personality . raphael has painted him here in the same pose as the prophet isaiah on the sistine ceiling although isaiah looks up , and here michelangelo 's heraclitus decidedly looks down . and so it 's so interesting that raphael is paying homage to michelangelo the great artist here personifying heraclitus , the philosopher who believed that all things were always in flux . that figure of heraclitus was actually added later . raphael finished the frescoe , added some wet plaster , and added in that figure . we should also note that raphael included himself here . that 's the young figure looking directly out at us in a black cap , and standing among some of the most important astronomers of all time . including ptolemy , who theorized about the movements of the planets . and zoroaster , who 's holding the celestial orb . we 're so far here from the medieval idea of the artist as a craftsman . here the artist is considered an intellectual on par with some the greatest thinkers in history , who can express these important ideas . so we have dozens of figures here without any sense of stiffness or repetition . raphael , like leonardo , in the last supper divides the figures into groups . each figure overlaps and moves easily between and amongst the others . my favorite two figures are the ones just behind euclid , one leaning against the wall with his leg crossed over the other who 's hurrying and writing some notes . the other leaning over and watching . there 's a wonderful sense of intimacy there . i think it 's a scene you could see walking along the hallway of any college or university . for all the free movement of the figures , the architecture itself is using a linear perspective in a rigorous way . you can follow the orthogonal either in the pavement , or in the cornices as they recede back . so the illusion of space here in incredible . look at the way that the decoration of the greek meander seems as if it goes back in space . what 's interesting though is if this architecture is harking back to any ancient tradition , it 's harking back to the roman tradition not to the greek 's who would never use barrel vaults in this way . nearby , bramante , raphael , michelangelo could see the baths of caracalla , or the basilica of manutius and constantine . there was roman architectural ruins all over the city that resembled what raphael has painted here . it 's so extraordinary that we 're celebrating here , the pantheon of great pagan thinkers . none of these men were christians . let 's take a quick look at the frescoes that 's opposite the school of athens known as the dispute . this frescoe represents theology , the study of the divine . figures here are divided between the heavenly and the earthly . close to the top we see god the father in the dome of heaven . below him , christ in this marvelous full-body halo , or mandorla , and he 's surrounded by the virgin mary on his right , and st. john the baptist on his left . just below , a dove against another gold disk , and this is the holy spirit , so all three together are the trinity . on either side of the dove are the four books of the gospels , matthew , mark , luke and john , that tell the story of the life of christ . on that wonderful bench of clouds sit prophets and saints . and we can actually recognize , for instance , moses holding the 10 commandments . and then another circle below contains the host , or the bread that is miraculously the body of christ during the mass . the bread functions as a link between heaven and earth . we can see how separated heaven and earth are in this fresco , and how important that link is . the figures along the bottom are popes , and bishops , and cardinals , and members of various religious orders . the fathers of the church , we can make out a portrait of dante , the great medieval poet . we have a sense of the figures on the bottom of the frescoe , coming to divine knowledge through the miracle of the host , and two figures on either end seem to be moving away from that divine knowledge . but there 's efforts being made to turn them around , to bring them back . so here , in the stanza della segnatura a room that functioned as the library for pope julius ii , a celebration of all aspects of human knowledge .
|
and so it 's so interesting that raphael is paying homage to michelangelo the great artist here personifying heraclitus , the philosopher who believed that all things were always in flux . that figure of heraclitus was actually added later . raphael finished the frescoe , added some wet plaster , and added in that figure .
|
who does the figure sprawled on the steps represent ?
|
we 're in the very crowded and not very large room called the stanza della segnatura that is not only dense with people , but it 's dense with imagery . we 're looking at frescoes by raphael . painted during the high renaissance at the same time that michelangelo was painting the sistine chapel ceiling just a few doors away . this room was originally a library , part of the papal apartments , that is the apartments where the pope lived . in order to imagine what this room would have looked like at the beginning of the 16th century , imagine away all of these people and imagine instead the lower walls lined with books . and also imagine quiet which is hard to do here , and an environment of learning where you could look up at what raphael painted here on the four walls which are the four branches of human knowledge , philosophy , having to do with things of this world . the philosophy at this time also meant what we know call the sciences . on the opposite wall theology , having to do with issues relating to god and the divine . and on the two other walls , poetry and justice . so these four areas of human knowledge symbolized by allegorical figures that we see on the ceiling , and it 's so clear that a few doors away is michelangelo because raphael is clearly looking at michelangelo 's figures on the ceiling of the sistine chapel especially the prophets and the sybils . what a moment in the high renaissance all commissioned thanks to pope julius ii . and think about what it means for theology to be presented equally with human knowledge . it is this extraordinarily liberal moment in church history . when humanist 's classical learning can be united with the teachings of the church . in the center of the school of athens , the frescoe that represents philosophy , we have the two great philosophers from antiquity in the center plato and aristotle surrounded by other great thinkers and philosophers and mathematicians from antiquity . virtually , every known great figure , but let 's start with the two in the center . we can tell plato from aristotle because plato is older . plato was , in fact , aristotle 's teacher , but also because he holds one of his own books , the timaeus . and aristotle holds his book , the ethics . both of those books represent the contrasting philosophies of these two men . plato was known for being interested in the ethereal , the theoretical , that which could not be seen , and , in fact , we see him pointing upward . this idea that the world of appearances is not the final truth , that there is a realm that is based on mathematics , on pure idea that is more true than the everyday world that we see . whereas , aristotle , his student , focused his attention on the observable , the actual , the physical . you 'll notice that his palm is down , and he seems to be saying , `` no , no , no , `` let 's pay attention to what is here . '' right , to what we can see and observe in the world . in fact , if you look at the colors that each of the figures wear , they refer to this division . plato wears red and purple , the purple referring to the ether what we would call the air , the red to fire , neither of which have weight . aristotle wears blue and brown that is the colors of earth and water which have gravity , which have weight . so the philosophers on either side of plato and aristotle continue this division . on the side of plato , we see philosophers concerned with issues of the ideal . for example , on the lower left we see pythagoras the great ancient mathematician who discovered laws of harmony in music , in mathematics . this idea that there is a reality that transcends the reality that we see . compare that to the lower right where we see euclid , the figure we associate with geometry . in fact , he seems to be drawing a geometric diagram for some very eager students . but he is interested in measure , that is the idea of the practical . euclid is modeled actually on a friend of raphael 's and that 's bramante the great architect asked by pope julius ii to provide a new model for a new saint peter 's . and in fact , appropriate to his reincarnation here as euclid , bramante 's design for saint peter 's was based on a perfect geometry of circles and squares . and is really visible in the architecture that raphael constructed for the school of athens . here we see an architecture that is very bramantian , but also very ancient roman . we have coffered barrel vaults , pilasters . this is a space that ennobles the figures that it contains . and we can see representations of classical sculpture in the niches on the left , that is on the platonic side . we see apollo , the god of the sun , the god of music , the god of poetry , things that would be appropriate to the platonic . in turn on the right , we see athena , the god of war and wisdom , who presumably is involved in the more practical affairs of man . all of this seems to me to be a place that is the opposite of the medieval where knowledge was something that was passed down by authority and one had to accept it . but here , on the walls of the papal apartments , we get this image of sharing knowledge and the history of the accumulation of knowledge all with figures who move beautifully who in their bodies represent a gracefulness that is a reflection of their inner wisdom and knowledge . you 'll notice that raphael has not placed any names within the painting . the only identifiers are perhaps the titles of the books that both plato and aristotle hold , and so we 're meant to understand who these figures are through their movement , through their dress . now , the artist has parted both groups to the left and the right so that the middle foreground is fairly empty . he does this , i think , for a couple of reasons . he wants the linear perspective at the bottom of the painting to balance the strong orthogonals at the top of the painting . he wants to make way for the advancement of plato and aristotle as they walk down the stairs , but we also have two figures in the foreground in the middle . we have diogenes , and most interestingly , we have the ancient philosopher , heraclitus , who seems to be writing and thinking quietly by himself . most of the other figures in this painting are engaged with others , but not this man . he seems to be lost in his own thoughts . well , and he is writing on a block of marble . in fact , his features are those of the great artist michelangelo known for his rather lonely and brooding personality . raphael has painted him here in the same pose as the prophet isaiah on the sistine ceiling although isaiah looks up , and here michelangelo 's heraclitus decidedly looks down . and so it 's so interesting that raphael is paying homage to michelangelo the great artist here personifying heraclitus , the philosopher who believed that all things were always in flux . that figure of heraclitus was actually added later . raphael finished the frescoe , added some wet plaster , and added in that figure . we should also note that raphael included himself here . that 's the young figure looking directly out at us in a black cap , and standing among some of the most important astronomers of all time . including ptolemy , who theorized about the movements of the planets . and zoroaster , who 's holding the celestial orb . we 're so far here from the medieval idea of the artist as a craftsman . here the artist is considered an intellectual on par with some the greatest thinkers in history , who can express these important ideas . so we have dozens of figures here without any sense of stiffness or repetition . raphael , like leonardo , in the last supper divides the figures into groups . each figure overlaps and moves easily between and amongst the others . my favorite two figures are the ones just behind euclid , one leaning against the wall with his leg crossed over the other who 's hurrying and writing some notes . the other leaning over and watching . there 's a wonderful sense of intimacy there . i think it 's a scene you could see walking along the hallway of any college or university . for all the free movement of the figures , the architecture itself is using a linear perspective in a rigorous way . you can follow the orthogonal either in the pavement , or in the cornices as they recede back . so the illusion of space here in incredible . look at the way that the decoration of the greek meander seems as if it goes back in space . what 's interesting though is if this architecture is harking back to any ancient tradition , it 's harking back to the roman tradition not to the greek 's who would never use barrel vaults in this way . nearby , bramante , raphael , michelangelo could see the baths of caracalla , or the basilica of manutius and constantine . there was roman architectural ruins all over the city that resembled what raphael has painted here . it 's so extraordinary that we 're celebrating here , the pantheon of great pagan thinkers . none of these men were christians . let 's take a quick look at the frescoes that 's opposite the school of athens known as the dispute . this frescoe represents theology , the study of the divine . figures here are divided between the heavenly and the earthly . close to the top we see god the father in the dome of heaven . below him , christ in this marvelous full-body halo , or mandorla , and he 's surrounded by the virgin mary on his right , and st. john the baptist on his left . just below , a dove against another gold disk , and this is the holy spirit , so all three together are the trinity . on either side of the dove are the four books of the gospels , matthew , mark , luke and john , that tell the story of the life of christ . on that wonderful bench of clouds sit prophets and saints . and we can actually recognize , for instance , moses holding the 10 commandments . and then another circle below contains the host , or the bread that is miraculously the body of christ during the mass . the bread functions as a link between heaven and earth . we can see how separated heaven and earth are in this fresco , and how important that link is . the figures along the bottom are popes , and bishops , and cardinals , and members of various religious orders . the fathers of the church , we can make out a portrait of dante , the great medieval poet . we have a sense of the figures on the bottom of the frescoe , coming to divine knowledge through the miracle of the host , and two figures on either end seem to be moving away from that divine knowledge . but there 's efforts being made to turn them around , to bring them back . so here , in the stanza della segnatura a room that functioned as the library for pope julius ii , a celebration of all aspects of human knowledge .
|
this idea that there is a reality that transcends the reality that we see . compare that to the lower right where we see euclid , the figure we associate with geometry . in fact , he seems to be drawing a geometric diagram for some very eager students .
|
who is the figure with a beard on the right in red ?
|
let 's talk about arteriolosclerosis . i 'm going to first point out a couple of important big picture ideas . why it is arteriolosclerosis matter ? well , we know that it 's basically soft , flexible kind of vessels like this that are very elastic and can expand , becoming very rigid , firm like pipes . and this is basically the big picture on why it matters . you lose compliance . in fact , let me write that in a different color -- lose compliance . and this is the big picture , right ? you want to make sure you do n't lose compliance . and that 's exactly what 's happening with arteriolosclerosis . and we also know where it 's happening because we have a little clue . we know based on the fact that we have an o-l-o here , this is different than arteriosclerosis . and that this process is happening in the small arteries and arterioles . and just to get a sense of size , i wanted to quickly put up here this is usually around 0.01 millimeters to about 1 millimeter . so pretty tiny and really kind of hard to see with your eyes . so i have drawn an example of what a cut vessel might look like if you were to look at it under a microscope . and inside of this vessel of course you 've got your blood cells here . and you 've got let 's say little platelets here . but you also have something very , very important that we do n't always talk about or think about , and that is you 've got little proteins here . so you 've got protein hanging out in the blood vessel . and these are serum proteins . serum , s-e-r-u-m , proteins . and all that means is that it 's in the blood or the serum . and that protein usually should stay in the middle of the vessel . it should n't be making its way into the blood vessel . but in arteriolosclerosis , the main problem , the core problem , is that this protein goes into this space , this tunica media space . so this is the second , the tunica media , and usually has just smooth muscle cells . but if the serum proteins go and settle in there , let 's say they 're able to make it through this barrier . this is the key barrier . this is the basement membrane . if they can make it through the basement membrane and settle into the tunica media , then you 've got a problem . in fact , let me draw a few proteins here . if these proteins can kind of make their way out here , then you 've got a problem . in fact , that is exactly how arteriolosclerosis happens . this is the process . so really if you look under a microscopic and you start seeing pink protein in the tunica media , you can be fairly certain that you have arteriolosclerosis happening . in fact , they even call it hyaline -- you might see this word hyaline -- arteriolosclerosis . and hyaline refers to the fact that under a microscope this vessel is going to look like it 's got some pink glassy stuff in the tunica media that does n't belong there . and that pink glassy stuff is the serum protein . and i put glassy in quotes because i do n't think that it looks very glassy . and i was always a little surprised that that 's what it means . but somebody at some point certainly thought it did . so the term hyaline is really just descriptive and arteriolosclerosis is the process . so now think about this for a second . think about the fact that if you have a protein moving from the lumen of the blood vessel into the tunica media , there 's got to be a couple different ways , or processes , that can happen logically , right ? so one logical way could be that maybe it 's being forced out . maybe the serum protein is being forced out of the lumen and has so much force that it 's actually driving it through the basement membrane . and that 's actually exactly what happens in people that have hypertension . so if you have hypertension , or high blood pressure , you have so much blood pressure , or so much force in the actual middle of the blood vessel , pushing out on the walls of the blood vessel -- and i 'll erase all this for a second -- that it literally forces these proteins outside . so that could be one way , right ? force the proteins out . and that 's what happens in hypertension . now , in diabetes , which is the other disease that you often hear about with hyaline arteriolosclerosis -- in diabetes , a different thing is happening . so let 's talk about how it happens in diabetes . again , the key is you 've got to figure out how did protein end up in the tunica media . so protein -- and i 'll put serum protein -- in tunica media . because that 's kind of a summary of what 's happening , right ? this is the key thing that 's happening . so in diabetes the way that happens is actually the basement membrane becomes leaky . so it 's not that you 're actually forcing the proteins out . you 're actually making it easier for them to get into the tunica media because the basement membrane -- basement membrane , i 'll just put bm -- becomes leaky . and how it becomes leaky is actually kind of an interesting story . and you 'll learn as i go through it step by step a couple of interesting facts . so fact number one , we know that there 's a lot of glucose in the blood vessels . so lots of glucose in the blood vessels of someone with diabetes . so let 's draw in some glucose . this purple stuff , these little dots , are going to be glucose . fair enough . so lots of glucose in the blood vessel . and step number two is that that glucose is going into these endothelial cells . so i 'm just going to draw a few of them here . so a few of these cells got a lot of this purple glucose in them . i know you 're thinking why in the world would these endothelial cells have glucose in them ? i thought that glucose only gets in with insulin . and the whole problem with diabetes is that you do n't have insulin allowing that glucose in or having some other difficulty getting that glucose in . so how is that glucose getting into those cells ? and here is kind of fact number one , and that is that glucose can get into the endothelial cells without the help of insulin . so endothelial cells take in glucose without -- there 's the big catch -- without insulin . so they do n't need insulin to take in the glucose . there have other ways of getting the glucose in there . so now you can see that if you have a lot of glucose in the blood vessels -- because every other cell in the body seems to need insulin to get it in and so it 's unable to get in . it 's kind of hanging out in the middle of the blood vessels . if it 's just hanging out there and the endothelial cells do n't need insulin to get the glucose in , then they 're going to be loaded with glucose , right ? so these endothelial cells become loaded with glucose . let me scroll up a little bit so we have some space . so they become loaded with glucose . and let 's draw that here . i 'm going to draw that out so that you can see it . these endothelial cells and below them we 've got the basement membrane here . this is the basement membrane . and these endothelial cells have a lot of glucose in them , right ? so this is all that glucose that they 've picked up . and they , of course , have proteins themselves . so they have proteins doing all sorts of interesting jobs . and so let 's draw some proteins in here . maybe this protein here and this protein here , maybe another protein here . so these proteins are hanging out doing their usual job in the cell , and all of a sudden you 've got lots of glucose in there . so what happens is that this glucose starts to stick onto , or bind onto , these proteins . and these proteins all of a sudden have tons of glucose on them that they do n't usually have . so these proteins are considered glycosylated . in fact , another longer term for it is that they turn into what they call advanced -- let me write it out here -- advanced glycosylation -- that 's kind of a fancy word -- glycosylation end product . so all that 's happened is that a normal protein , normal protein or enzyme , that was doing its job -- in fact , let me stay consistent here with the colors . so normal protein that was doing its job in the cell , in these endothelial cells , becomes what we call an age , advanced glycosylation end product . so these ages are basically the same protein , but now with glucose on them . they actually do n't do as good a job as they 're supposed to . that 's kind of the bottom line . they are n't working the way they should . and one of their jobs is to make sure that that basement membrane is doing a good job of forming a barrier . and that basement membrane becomes very leaky . so the basement membrane actually becomes thicker -- which is counterintuitive , right -- becomes thicker . because you think if it 's thicker it 's doing a better job being a barrier , but actually it 's a worse job being a barrier -- and leaky . and this is really the important issue . because that leakiness is what 's allowing all the serum proteins to come across and settle into the tunica media . so let 's stop there and we 'll pick up .
|
so you 've got protein hanging out in the blood vessel . and these are serum proteins . serum , s-e-r-u-m , proteins .
|
what do serum proteins do when they 're not causing arteriolosclerosis ?
|
let 's talk about arteriolosclerosis . i 'm going to first point out a couple of important big picture ideas . why it is arteriolosclerosis matter ? well , we know that it 's basically soft , flexible kind of vessels like this that are very elastic and can expand , becoming very rigid , firm like pipes . and this is basically the big picture on why it matters . you lose compliance . in fact , let me write that in a different color -- lose compliance . and this is the big picture , right ? you want to make sure you do n't lose compliance . and that 's exactly what 's happening with arteriolosclerosis . and we also know where it 's happening because we have a little clue . we know based on the fact that we have an o-l-o here , this is different than arteriosclerosis . and that this process is happening in the small arteries and arterioles . and just to get a sense of size , i wanted to quickly put up here this is usually around 0.01 millimeters to about 1 millimeter . so pretty tiny and really kind of hard to see with your eyes . so i have drawn an example of what a cut vessel might look like if you were to look at it under a microscope . and inside of this vessel of course you 've got your blood cells here . and you 've got let 's say little platelets here . but you also have something very , very important that we do n't always talk about or think about , and that is you 've got little proteins here . so you 've got protein hanging out in the blood vessel . and these are serum proteins . serum , s-e-r-u-m , proteins . and all that means is that it 's in the blood or the serum . and that protein usually should stay in the middle of the vessel . it should n't be making its way into the blood vessel . but in arteriolosclerosis , the main problem , the core problem , is that this protein goes into this space , this tunica media space . so this is the second , the tunica media , and usually has just smooth muscle cells . but if the serum proteins go and settle in there , let 's say they 're able to make it through this barrier . this is the key barrier . this is the basement membrane . if they can make it through the basement membrane and settle into the tunica media , then you 've got a problem . in fact , let me draw a few proteins here . if these proteins can kind of make their way out here , then you 've got a problem . in fact , that is exactly how arteriolosclerosis happens . this is the process . so really if you look under a microscopic and you start seeing pink protein in the tunica media , you can be fairly certain that you have arteriolosclerosis happening . in fact , they even call it hyaline -- you might see this word hyaline -- arteriolosclerosis . and hyaline refers to the fact that under a microscope this vessel is going to look like it 's got some pink glassy stuff in the tunica media that does n't belong there . and that pink glassy stuff is the serum protein . and i put glassy in quotes because i do n't think that it looks very glassy . and i was always a little surprised that that 's what it means . but somebody at some point certainly thought it did . so the term hyaline is really just descriptive and arteriolosclerosis is the process . so now think about this for a second . think about the fact that if you have a protein moving from the lumen of the blood vessel into the tunica media , there 's got to be a couple different ways , or processes , that can happen logically , right ? so one logical way could be that maybe it 's being forced out . maybe the serum protein is being forced out of the lumen and has so much force that it 's actually driving it through the basement membrane . and that 's actually exactly what happens in people that have hypertension . so if you have hypertension , or high blood pressure , you have so much blood pressure , or so much force in the actual middle of the blood vessel , pushing out on the walls of the blood vessel -- and i 'll erase all this for a second -- that it literally forces these proteins outside . so that could be one way , right ? force the proteins out . and that 's what happens in hypertension . now , in diabetes , which is the other disease that you often hear about with hyaline arteriolosclerosis -- in diabetes , a different thing is happening . so let 's talk about how it happens in diabetes . again , the key is you 've got to figure out how did protein end up in the tunica media . so protein -- and i 'll put serum protein -- in tunica media . because that 's kind of a summary of what 's happening , right ? this is the key thing that 's happening . so in diabetes the way that happens is actually the basement membrane becomes leaky . so it 's not that you 're actually forcing the proteins out . you 're actually making it easier for them to get into the tunica media because the basement membrane -- basement membrane , i 'll just put bm -- becomes leaky . and how it becomes leaky is actually kind of an interesting story . and you 'll learn as i go through it step by step a couple of interesting facts . so fact number one , we know that there 's a lot of glucose in the blood vessels . so lots of glucose in the blood vessels of someone with diabetes . so let 's draw in some glucose . this purple stuff , these little dots , are going to be glucose . fair enough . so lots of glucose in the blood vessel . and step number two is that that glucose is going into these endothelial cells . so i 'm just going to draw a few of them here . so a few of these cells got a lot of this purple glucose in them . i know you 're thinking why in the world would these endothelial cells have glucose in them ? i thought that glucose only gets in with insulin . and the whole problem with diabetes is that you do n't have insulin allowing that glucose in or having some other difficulty getting that glucose in . so how is that glucose getting into those cells ? and here is kind of fact number one , and that is that glucose can get into the endothelial cells without the help of insulin . so endothelial cells take in glucose without -- there 's the big catch -- without insulin . so they do n't need insulin to take in the glucose . there have other ways of getting the glucose in there . so now you can see that if you have a lot of glucose in the blood vessels -- because every other cell in the body seems to need insulin to get it in and so it 's unable to get in . it 's kind of hanging out in the middle of the blood vessels . if it 's just hanging out there and the endothelial cells do n't need insulin to get the glucose in , then they 're going to be loaded with glucose , right ? so these endothelial cells become loaded with glucose . let me scroll up a little bit so we have some space . so they become loaded with glucose . and let 's draw that here . i 'm going to draw that out so that you can see it . these endothelial cells and below them we 've got the basement membrane here . this is the basement membrane . and these endothelial cells have a lot of glucose in them , right ? so this is all that glucose that they 've picked up . and they , of course , have proteins themselves . so they have proteins doing all sorts of interesting jobs . and so let 's draw some proteins in here . maybe this protein here and this protein here , maybe another protein here . so these proteins are hanging out doing their usual job in the cell , and all of a sudden you 've got lots of glucose in there . so what happens is that this glucose starts to stick onto , or bind onto , these proteins . and these proteins all of a sudden have tons of glucose on them that they do n't usually have . so these proteins are considered glycosylated . in fact , another longer term for it is that they turn into what they call advanced -- let me write it out here -- advanced glycosylation -- that 's kind of a fancy word -- glycosylation end product . so all that 's happened is that a normal protein , normal protein or enzyme , that was doing its job -- in fact , let me stay consistent here with the colors . so normal protein that was doing its job in the cell , in these endothelial cells , becomes what we call an age , advanced glycosylation end product . so these ages are basically the same protein , but now with glucose on them . they actually do n't do as good a job as they 're supposed to . that 's kind of the bottom line . they are n't working the way they should . and one of their jobs is to make sure that that basement membrane is doing a good job of forming a barrier . and that basement membrane becomes very leaky . so the basement membrane actually becomes thicker -- which is counterintuitive , right -- becomes thicker . because you think if it 's thicker it 's doing a better job being a barrier , but actually it 's a worse job being a barrier -- and leaky . and this is really the important issue . because that leakiness is what 's allowing all the serum proteins to come across and settle into the tunica media . so let 's stop there and we 'll pick up .
|
and you 'll learn as i go through it step by step a couple of interesting facts . so fact number one , we know that there 's a lot of glucose in the blood vessels . so lots of glucose in the blood vessels of someone with diabetes . so let 's draw in some glucose .
|
how does your body reflect the cells back into the body once being rotated through the blood vessels ?
|
let 's talk about arteriolosclerosis . i 'm going to first point out a couple of important big picture ideas . why it is arteriolosclerosis matter ? well , we know that it 's basically soft , flexible kind of vessels like this that are very elastic and can expand , becoming very rigid , firm like pipes . and this is basically the big picture on why it matters . you lose compliance . in fact , let me write that in a different color -- lose compliance . and this is the big picture , right ? you want to make sure you do n't lose compliance . and that 's exactly what 's happening with arteriolosclerosis . and we also know where it 's happening because we have a little clue . we know based on the fact that we have an o-l-o here , this is different than arteriosclerosis . and that this process is happening in the small arteries and arterioles . and just to get a sense of size , i wanted to quickly put up here this is usually around 0.01 millimeters to about 1 millimeter . so pretty tiny and really kind of hard to see with your eyes . so i have drawn an example of what a cut vessel might look like if you were to look at it under a microscope . and inside of this vessel of course you 've got your blood cells here . and you 've got let 's say little platelets here . but you also have something very , very important that we do n't always talk about or think about , and that is you 've got little proteins here . so you 've got protein hanging out in the blood vessel . and these are serum proteins . serum , s-e-r-u-m , proteins . and all that means is that it 's in the blood or the serum . and that protein usually should stay in the middle of the vessel . it should n't be making its way into the blood vessel . but in arteriolosclerosis , the main problem , the core problem , is that this protein goes into this space , this tunica media space . so this is the second , the tunica media , and usually has just smooth muscle cells . but if the serum proteins go and settle in there , let 's say they 're able to make it through this barrier . this is the key barrier . this is the basement membrane . if they can make it through the basement membrane and settle into the tunica media , then you 've got a problem . in fact , let me draw a few proteins here . if these proteins can kind of make their way out here , then you 've got a problem . in fact , that is exactly how arteriolosclerosis happens . this is the process . so really if you look under a microscopic and you start seeing pink protein in the tunica media , you can be fairly certain that you have arteriolosclerosis happening . in fact , they even call it hyaline -- you might see this word hyaline -- arteriolosclerosis . and hyaline refers to the fact that under a microscope this vessel is going to look like it 's got some pink glassy stuff in the tunica media that does n't belong there . and that pink glassy stuff is the serum protein . and i put glassy in quotes because i do n't think that it looks very glassy . and i was always a little surprised that that 's what it means . but somebody at some point certainly thought it did . so the term hyaline is really just descriptive and arteriolosclerosis is the process . so now think about this for a second . think about the fact that if you have a protein moving from the lumen of the blood vessel into the tunica media , there 's got to be a couple different ways , or processes , that can happen logically , right ? so one logical way could be that maybe it 's being forced out . maybe the serum protein is being forced out of the lumen and has so much force that it 's actually driving it through the basement membrane . and that 's actually exactly what happens in people that have hypertension . so if you have hypertension , or high blood pressure , you have so much blood pressure , or so much force in the actual middle of the blood vessel , pushing out on the walls of the blood vessel -- and i 'll erase all this for a second -- that it literally forces these proteins outside . so that could be one way , right ? force the proteins out . and that 's what happens in hypertension . now , in diabetes , which is the other disease that you often hear about with hyaline arteriolosclerosis -- in diabetes , a different thing is happening . so let 's talk about how it happens in diabetes . again , the key is you 've got to figure out how did protein end up in the tunica media . so protein -- and i 'll put serum protein -- in tunica media . because that 's kind of a summary of what 's happening , right ? this is the key thing that 's happening . so in diabetes the way that happens is actually the basement membrane becomes leaky . so it 's not that you 're actually forcing the proteins out . you 're actually making it easier for them to get into the tunica media because the basement membrane -- basement membrane , i 'll just put bm -- becomes leaky . and how it becomes leaky is actually kind of an interesting story . and you 'll learn as i go through it step by step a couple of interesting facts . so fact number one , we know that there 's a lot of glucose in the blood vessels . so lots of glucose in the blood vessels of someone with diabetes . so let 's draw in some glucose . this purple stuff , these little dots , are going to be glucose . fair enough . so lots of glucose in the blood vessel . and step number two is that that glucose is going into these endothelial cells . so i 'm just going to draw a few of them here . so a few of these cells got a lot of this purple glucose in them . i know you 're thinking why in the world would these endothelial cells have glucose in them ? i thought that glucose only gets in with insulin . and the whole problem with diabetes is that you do n't have insulin allowing that glucose in or having some other difficulty getting that glucose in . so how is that glucose getting into those cells ? and here is kind of fact number one , and that is that glucose can get into the endothelial cells without the help of insulin . so endothelial cells take in glucose without -- there 's the big catch -- without insulin . so they do n't need insulin to take in the glucose . there have other ways of getting the glucose in there . so now you can see that if you have a lot of glucose in the blood vessels -- because every other cell in the body seems to need insulin to get it in and so it 's unable to get in . it 's kind of hanging out in the middle of the blood vessels . if it 's just hanging out there and the endothelial cells do n't need insulin to get the glucose in , then they 're going to be loaded with glucose , right ? so these endothelial cells become loaded with glucose . let me scroll up a little bit so we have some space . so they become loaded with glucose . and let 's draw that here . i 'm going to draw that out so that you can see it . these endothelial cells and below them we 've got the basement membrane here . this is the basement membrane . and these endothelial cells have a lot of glucose in them , right ? so this is all that glucose that they 've picked up . and they , of course , have proteins themselves . so they have proteins doing all sorts of interesting jobs . and so let 's draw some proteins in here . maybe this protein here and this protein here , maybe another protein here . so these proteins are hanging out doing their usual job in the cell , and all of a sudden you 've got lots of glucose in there . so what happens is that this glucose starts to stick onto , or bind onto , these proteins . and these proteins all of a sudden have tons of glucose on them that they do n't usually have . so these proteins are considered glycosylated . in fact , another longer term for it is that they turn into what they call advanced -- let me write it out here -- advanced glycosylation -- that 's kind of a fancy word -- glycosylation end product . so all that 's happened is that a normal protein , normal protein or enzyme , that was doing its job -- in fact , let me stay consistent here with the colors . so normal protein that was doing its job in the cell , in these endothelial cells , becomes what we call an age , advanced glycosylation end product . so these ages are basically the same protein , but now with glucose on them . they actually do n't do as good a job as they 're supposed to . that 's kind of the bottom line . they are n't working the way they should . and one of their jobs is to make sure that that basement membrane is doing a good job of forming a barrier . and that basement membrane becomes very leaky . so the basement membrane actually becomes thicker -- which is counterintuitive , right -- becomes thicker . because you think if it 's thicker it 's doing a better job being a barrier , but actually it 's a worse job being a barrier -- and leaky . and this is really the important issue . because that leakiness is what 's allowing all the serum proteins to come across and settle into the tunica media . so let 's stop there and we 'll pick up .
|
and one of their jobs is to make sure that that basement membrane is doing a good job of forming a barrier . and that basement membrane becomes very leaky . so the basement membrane actually becomes thicker -- which is counterintuitive , right -- becomes thicker .
|
how can the basement membrane becomes leaky ?
|
let 's talk about arteriolosclerosis . i 'm going to first point out a couple of important big picture ideas . why it is arteriolosclerosis matter ? well , we know that it 's basically soft , flexible kind of vessels like this that are very elastic and can expand , becoming very rigid , firm like pipes . and this is basically the big picture on why it matters . you lose compliance . in fact , let me write that in a different color -- lose compliance . and this is the big picture , right ? you want to make sure you do n't lose compliance . and that 's exactly what 's happening with arteriolosclerosis . and we also know where it 's happening because we have a little clue . we know based on the fact that we have an o-l-o here , this is different than arteriosclerosis . and that this process is happening in the small arteries and arterioles . and just to get a sense of size , i wanted to quickly put up here this is usually around 0.01 millimeters to about 1 millimeter . so pretty tiny and really kind of hard to see with your eyes . so i have drawn an example of what a cut vessel might look like if you were to look at it under a microscope . and inside of this vessel of course you 've got your blood cells here . and you 've got let 's say little platelets here . but you also have something very , very important that we do n't always talk about or think about , and that is you 've got little proteins here . so you 've got protein hanging out in the blood vessel . and these are serum proteins . serum , s-e-r-u-m , proteins . and all that means is that it 's in the blood or the serum . and that protein usually should stay in the middle of the vessel . it should n't be making its way into the blood vessel . but in arteriolosclerosis , the main problem , the core problem , is that this protein goes into this space , this tunica media space . so this is the second , the tunica media , and usually has just smooth muscle cells . but if the serum proteins go and settle in there , let 's say they 're able to make it through this barrier . this is the key barrier . this is the basement membrane . if they can make it through the basement membrane and settle into the tunica media , then you 've got a problem . in fact , let me draw a few proteins here . if these proteins can kind of make their way out here , then you 've got a problem . in fact , that is exactly how arteriolosclerosis happens . this is the process . so really if you look under a microscopic and you start seeing pink protein in the tunica media , you can be fairly certain that you have arteriolosclerosis happening . in fact , they even call it hyaline -- you might see this word hyaline -- arteriolosclerosis . and hyaline refers to the fact that under a microscope this vessel is going to look like it 's got some pink glassy stuff in the tunica media that does n't belong there . and that pink glassy stuff is the serum protein . and i put glassy in quotes because i do n't think that it looks very glassy . and i was always a little surprised that that 's what it means . but somebody at some point certainly thought it did . so the term hyaline is really just descriptive and arteriolosclerosis is the process . so now think about this for a second . think about the fact that if you have a protein moving from the lumen of the blood vessel into the tunica media , there 's got to be a couple different ways , or processes , that can happen logically , right ? so one logical way could be that maybe it 's being forced out . maybe the serum protein is being forced out of the lumen and has so much force that it 's actually driving it through the basement membrane . and that 's actually exactly what happens in people that have hypertension . so if you have hypertension , or high blood pressure , you have so much blood pressure , or so much force in the actual middle of the blood vessel , pushing out on the walls of the blood vessel -- and i 'll erase all this for a second -- that it literally forces these proteins outside . so that could be one way , right ? force the proteins out . and that 's what happens in hypertension . now , in diabetes , which is the other disease that you often hear about with hyaline arteriolosclerosis -- in diabetes , a different thing is happening . so let 's talk about how it happens in diabetes . again , the key is you 've got to figure out how did protein end up in the tunica media . so protein -- and i 'll put serum protein -- in tunica media . because that 's kind of a summary of what 's happening , right ? this is the key thing that 's happening . so in diabetes the way that happens is actually the basement membrane becomes leaky . so it 's not that you 're actually forcing the proteins out . you 're actually making it easier for them to get into the tunica media because the basement membrane -- basement membrane , i 'll just put bm -- becomes leaky . and how it becomes leaky is actually kind of an interesting story . and you 'll learn as i go through it step by step a couple of interesting facts . so fact number one , we know that there 's a lot of glucose in the blood vessels . so lots of glucose in the blood vessels of someone with diabetes . so let 's draw in some glucose . this purple stuff , these little dots , are going to be glucose . fair enough . so lots of glucose in the blood vessel . and step number two is that that glucose is going into these endothelial cells . so i 'm just going to draw a few of them here . so a few of these cells got a lot of this purple glucose in them . i know you 're thinking why in the world would these endothelial cells have glucose in them ? i thought that glucose only gets in with insulin . and the whole problem with diabetes is that you do n't have insulin allowing that glucose in or having some other difficulty getting that glucose in . so how is that glucose getting into those cells ? and here is kind of fact number one , and that is that glucose can get into the endothelial cells without the help of insulin . so endothelial cells take in glucose without -- there 's the big catch -- without insulin . so they do n't need insulin to take in the glucose . there have other ways of getting the glucose in there . so now you can see that if you have a lot of glucose in the blood vessels -- because every other cell in the body seems to need insulin to get it in and so it 's unable to get in . it 's kind of hanging out in the middle of the blood vessels . if it 's just hanging out there and the endothelial cells do n't need insulin to get the glucose in , then they 're going to be loaded with glucose , right ? so these endothelial cells become loaded with glucose . let me scroll up a little bit so we have some space . so they become loaded with glucose . and let 's draw that here . i 'm going to draw that out so that you can see it . these endothelial cells and below them we 've got the basement membrane here . this is the basement membrane . and these endothelial cells have a lot of glucose in them , right ? so this is all that glucose that they 've picked up . and they , of course , have proteins themselves . so they have proteins doing all sorts of interesting jobs . and so let 's draw some proteins in here . maybe this protein here and this protein here , maybe another protein here . so these proteins are hanging out doing their usual job in the cell , and all of a sudden you 've got lots of glucose in there . so what happens is that this glucose starts to stick onto , or bind onto , these proteins . and these proteins all of a sudden have tons of glucose on them that they do n't usually have . so these proteins are considered glycosylated . in fact , another longer term for it is that they turn into what they call advanced -- let me write it out here -- advanced glycosylation -- that 's kind of a fancy word -- glycosylation end product . so all that 's happened is that a normal protein , normal protein or enzyme , that was doing its job -- in fact , let me stay consistent here with the colors . so normal protein that was doing its job in the cell , in these endothelial cells , becomes what we call an age , advanced glycosylation end product . so these ages are basically the same protein , but now with glucose on them . they actually do n't do as good a job as they 're supposed to . that 's kind of the bottom line . they are n't working the way they should . and one of their jobs is to make sure that that basement membrane is doing a good job of forming a barrier . and that basement membrane becomes very leaky . so the basement membrane actually becomes thicker -- which is counterintuitive , right -- becomes thicker . because you think if it 's thicker it 's doing a better job being a barrier , but actually it 's a worse job being a barrier -- and leaky . and this is really the important issue . because that leakiness is what 's allowing all the serum proteins to come across and settle into the tunica media . so let 's stop there and we 'll pick up .
|
and here is kind of fact number one , and that is that glucose can get into the endothelial cells without the help of insulin . so endothelial cells take in glucose without -- there 's the big catch -- without insulin . so they do n't need insulin to take in the glucose . there have other ways of getting the glucose in there .
|
are there any other cells other than endothelial cells that do n't need insulin to take in glucose ?
|
let 's talk about arteriolosclerosis . i 'm going to first point out a couple of important big picture ideas . why it is arteriolosclerosis matter ? well , we know that it 's basically soft , flexible kind of vessels like this that are very elastic and can expand , becoming very rigid , firm like pipes . and this is basically the big picture on why it matters . you lose compliance . in fact , let me write that in a different color -- lose compliance . and this is the big picture , right ? you want to make sure you do n't lose compliance . and that 's exactly what 's happening with arteriolosclerosis . and we also know where it 's happening because we have a little clue . we know based on the fact that we have an o-l-o here , this is different than arteriosclerosis . and that this process is happening in the small arteries and arterioles . and just to get a sense of size , i wanted to quickly put up here this is usually around 0.01 millimeters to about 1 millimeter . so pretty tiny and really kind of hard to see with your eyes . so i have drawn an example of what a cut vessel might look like if you were to look at it under a microscope . and inside of this vessel of course you 've got your blood cells here . and you 've got let 's say little platelets here . but you also have something very , very important that we do n't always talk about or think about , and that is you 've got little proteins here . so you 've got protein hanging out in the blood vessel . and these are serum proteins . serum , s-e-r-u-m , proteins . and all that means is that it 's in the blood or the serum . and that protein usually should stay in the middle of the vessel . it should n't be making its way into the blood vessel . but in arteriolosclerosis , the main problem , the core problem , is that this protein goes into this space , this tunica media space . so this is the second , the tunica media , and usually has just smooth muscle cells . but if the serum proteins go and settle in there , let 's say they 're able to make it through this barrier . this is the key barrier . this is the basement membrane . if they can make it through the basement membrane and settle into the tunica media , then you 've got a problem . in fact , let me draw a few proteins here . if these proteins can kind of make their way out here , then you 've got a problem . in fact , that is exactly how arteriolosclerosis happens . this is the process . so really if you look under a microscopic and you start seeing pink protein in the tunica media , you can be fairly certain that you have arteriolosclerosis happening . in fact , they even call it hyaline -- you might see this word hyaline -- arteriolosclerosis . and hyaline refers to the fact that under a microscope this vessel is going to look like it 's got some pink glassy stuff in the tunica media that does n't belong there . and that pink glassy stuff is the serum protein . and i put glassy in quotes because i do n't think that it looks very glassy . and i was always a little surprised that that 's what it means . but somebody at some point certainly thought it did . so the term hyaline is really just descriptive and arteriolosclerosis is the process . so now think about this for a second . think about the fact that if you have a protein moving from the lumen of the blood vessel into the tunica media , there 's got to be a couple different ways , or processes , that can happen logically , right ? so one logical way could be that maybe it 's being forced out . maybe the serum protein is being forced out of the lumen and has so much force that it 's actually driving it through the basement membrane . and that 's actually exactly what happens in people that have hypertension . so if you have hypertension , or high blood pressure , you have so much blood pressure , or so much force in the actual middle of the blood vessel , pushing out on the walls of the blood vessel -- and i 'll erase all this for a second -- that it literally forces these proteins outside . so that could be one way , right ? force the proteins out . and that 's what happens in hypertension . now , in diabetes , which is the other disease that you often hear about with hyaline arteriolosclerosis -- in diabetes , a different thing is happening . so let 's talk about how it happens in diabetes . again , the key is you 've got to figure out how did protein end up in the tunica media . so protein -- and i 'll put serum protein -- in tunica media . because that 's kind of a summary of what 's happening , right ? this is the key thing that 's happening . so in diabetes the way that happens is actually the basement membrane becomes leaky . so it 's not that you 're actually forcing the proteins out . you 're actually making it easier for them to get into the tunica media because the basement membrane -- basement membrane , i 'll just put bm -- becomes leaky . and how it becomes leaky is actually kind of an interesting story . and you 'll learn as i go through it step by step a couple of interesting facts . so fact number one , we know that there 's a lot of glucose in the blood vessels . so lots of glucose in the blood vessels of someone with diabetes . so let 's draw in some glucose . this purple stuff , these little dots , are going to be glucose . fair enough . so lots of glucose in the blood vessel . and step number two is that that glucose is going into these endothelial cells . so i 'm just going to draw a few of them here . so a few of these cells got a lot of this purple glucose in them . i know you 're thinking why in the world would these endothelial cells have glucose in them ? i thought that glucose only gets in with insulin . and the whole problem with diabetes is that you do n't have insulin allowing that glucose in or having some other difficulty getting that glucose in . so how is that glucose getting into those cells ? and here is kind of fact number one , and that is that glucose can get into the endothelial cells without the help of insulin . so endothelial cells take in glucose without -- there 's the big catch -- without insulin . so they do n't need insulin to take in the glucose . there have other ways of getting the glucose in there . so now you can see that if you have a lot of glucose in the blood vessels -- because every other cell in the body seems to need insulin to get it in and so it 's unable to get in . it 's kind of hanging out in the middle of the blood vessels . if it 's just hanging out there and the endothelial cells do n't need insulin to get the glucose in , then they 're going to be loaded with glucose , right ? so these endothelial cells become loaded with glucose . let me scroll up a little bit so we have some space . so they become loaded with glucose . and let 's draw that here . i 'm going to draw that out so that you can see it . these endothelial cells and below them we 've got the basement membrane here . this is the basement membrane . and these endothelial cells have a lot of glucose in them , right ? so this is all that glucose that they 've picked up . and they , of course , have proteins themselves . so they have proteins doing all sorts of interesting jobs . and so let 's draw some proteins in here . maybe this protein here and this protein here , maybe another protein here . so these proteins are hanging out doing their usual job in the cell , and all of a sudden you 've got lots of glucose in there . so what happens is that this glucose starts to stick onto , or bind onto , these proteins . and these proteins all of a sudden have tons of glucose on them that they do n't usually have . so these proteins are considered glycosylated . in fact , another longer term for it is that they turn into what they call advanced -- let me write it out here -- advanced glycosylation -- that 's kind of a fancy word -- glycosylation end product . so all that 's happened is that a normal protein , normal protein or enzyme , that was doing its job -- in fact , let me stay consistent here with the colors . so normal protein that was doing its job in the cell , in these endothelial cells , becomes what we call an age , advanced glycosylation end product . so these ages are basically the same protein , but now with glucose on them . they actually do n't do as good a job as they 're supposed to . that 's kind of the bottom line . they are n't working the way they should . and one of their jobs is to make sure that that basement membrane is doing a good job of forming a barrier . and that basement membrane becomes very leaky . so the basement membrane actually becomes thicker -- which is counterintuitive , right -- becomes thicker . because you think if it 's thicker it 's doing a better job being a barrier , but actually it 's a worse job being a barrier -- and leaky . and this is really the important issue . because that leakiness is what 's allowing all the serum proteins to come across and settle into the tunica media . so let 's stop there and we 'll pick up .
|
so you 've got protein hanging out in the blood vessel . and these are serum proteins . serum , s-e-r-u-m , proteins .
|
do the serum proteins themselves physically do anything when in the t. media ?
|
for the past 12 weeks , we 've been investigating our living planet together , learning how it works on many levels , how populations of organisms interact , how communities thrive and ecosystems change , and how humans are wrecking the nice , perfectly functioning systems earth has been using for hundreds of thousands of years . and now it 's graduation day . this here is like the commencement speech where i talk to you about the future and our role in it and how what we 're doing to the planet is totally awful , but we 're taking steps to undo some of the damage that we 've done . so what better way to wrap up our series on ecology than by taking a look at the growing fields of conservation biology and restoration ecology . these disciplines use all the kung fu moves that we 've learned about in the past 11 weeks and apply them to protecting ecosystems and cleaning up the messes that we 've already made . and one of the main things they teach us is that doing these things is difficult , like in the way that uncooking bacon is difficult . so let 's look at what we 're doing and try to uncook this unbelievably large pile of bacon we 've made . just outside of missoula , montana , where i live , we 've got a superfund site . not super-fun . superfund , a hazardous waste site that the government is in charge of cleaning up . the mess here was made more than 100 years ago , when there was a dam in the clark fork river behind me called the milltown dam . this part of montana has a long history of copper mining , and back in 1908 , there was a humongous flood that washed about 4.5 million cubic meters of mine tailings chock full of arsenic and toxic heavy metals into the clark fork river . and most of it washed into the reservoir created by the milltown dam . i mean , actually it was lucky that the dam was there -- it had only been completed six months before -- or the whole river system all the way to the pacific ocean would have been a toxic mess . as it happened , though , only about 160 kilometers of the river was all toxic , messed up . a lot of it recuperated over time . but all that nasty hazardous waste was still sitting behind milltown dam . and some of it leached into the groundwater that started polluting nearby residents ' wells . so scientists spent decades studying the extent of the damage caused by the waste and coming up with ways to fix it . and from 2006 to 2010 , engineers carefully removed all the toxic sediment as well as the dam itself . now this stretch of the clark fork river runs unimpeded for the first time in over a century , and the restored area where the dam used to be is being turned into a state park . efforts like this show us conservation biology and restoration ecology in action . conservation biology involves measuring the biodiversity of an ecosystem and determining how to protect it . in this case , it was used to size up the health of fish populations in the clark fork river , which were severely affected by the waste behind the dam , and the damn blocking their access to spawning grounds upstream , and figuring out how to protect them during the dam 's removal . restoration ecology , meanwhile , is the science of restoring broken ecosystems , like taking an interrupted , polluted river and turning it into what you see taking shape here . these do-gooder , fix-it-up sciences are practical rather than theoretical , by which i mean in order to fix something that 's broken , you 've got to have a good idea of what 's making it work to begin with . if something goes wrong with the expansion of the universe , we would n't be able to fix it because we have no idea at all what 's making all that happen . so in order to fix a failing ecosystem , you have to figure out what was holding it together in the first place . and the glue that holds every ecosystem together is biodiversity . but then , of course , biodiversity can mean many different things . so far , we 've generally used it to mean species diversity , or the variety of species in an ecosystem . but there are also other ways of talking about biodiversity that help conservation biologists and restoration ecologists figure out how to save species and repair ecosystems . in addition to diversity of species , ecologists look at genetic diversity within a species , as a whole and between populations . genetic diversity is important because it makes evolution possible by allowing a species to adapt to new situations like disease and climate change . and then another level of biodiversity has to do with ecosystem diversity , or the variety of different ecosystems within an area . a big , old forest , for example , can host several different kinds of ecosystems , like wetland , alpine , and aquatic ones . just like we talked about when we covered ecological succession , the more little pockets you 've got performing different functions , the more resilient the region will be as a whole . so , yeah . understanding all of this is really important to figuring out how to repair an ecosystem that is in shambles . but how do conservation biologists take the information about what makes an ecosystem tick and use it to save the place from going under ? well , there 's more than one way to approach this problem . one way is called small population conservation . this approach focuses on identifying species and populations that are really small , and tries to help boost their numbers and genetic diversity . low population and low genetic diversity are kind of a death knell for a species . they actually feed off each other , one problem making the other problem worse , ultimately causing a species to spiral into extinction . see , when a tiny little population suffers from inbreeding or genetic drift , that is , a shift in its overall genetic makeup , this leads to even less diversity , which in turn causes lower reproduction rates and higher mortality rates , which makes the population smaller still . this terrible little dynamic is known by the awesome term extinction vortex . the next step is to figure out how small a population is too small . ecologists do this by calculating what 's called the minimum viable population , which is the smallest size at which a population can survive and sustain itself . to get at this number , you have to know the real breeding population of , say , grizzly bears in yellowstone national park . and then you figure out everything you can about a grizzly 's life history , how long they live , who gets to breed the most , how often they can have babies , that kind of thing . after all that information is collected , ecologists can run the numbers and figure out that , for the grizzlies in yellowstone , a population of , say hypothetically , 90 bears would have about a 95 % chance of surviving for 100 years . but if there were a population of 100 bears , the population would likely be able to survive for 200 years . something to note , ecology involves a lot of math . so if you 're interested in this , that 's just the way it is . so that 's the small population approach to conservation . another way of preserving biodiversity focuses on populations whose numbers are in decline , no matter how large the original population was . this is known as declining population conservation , and it involves answering a series of related questions that get at the root of what 's causing an organism 's numbers to nosedive . first , you have to determine whether the population 's actually declining . then you have to figure out how big the population historically was and what its requirements were . and finally , you have to get at what 's causing the decline and figure out how to address it . milltown dam actually gives us a good example of this process . in the winter of 1996 , authorities had to release some of the water behind the dam as an emergency measure because of a big ice floe in the river that was threatening to break the dam . but when they released the water , a bunch of toxic sediment went with it , which raised the copper concentrations downriver to almost 43 times what state standards allowed . as a result , it 's estimated that about half of the fish downstream died . half of the fish , dead . and researchers have been monitoring the decline in populations ever since . this information was really helpful in determining what to do with the dam because we knew what the fish population was like before and after the release of the sediment . it was decided that it would be best to get the dam out as soon as possible rather than risk another 1996 scenario . which brings me to the place where conservation biology and restoration ecology intersect . restoration ecology is kind of where the rubber meets the road in conservation biology . it comes up with possible solutions for ecological problems . now , short of a time machine , which i 'm working on , you ca n't really get a natural environment exactly the way that it used to be . but you can at least get rid of whatever is causing the problem , and help recreate some of the elements that the ecosystem needs to function properly . all of this involves a whole suite of strategies . for instance , what 's happening in milltown is an example of structural restoration , basically the removal and cleanup of whatever human impact was causing the problem , in this case , the dam and the toxic sediments behind it . and then the rebuilding of the historical natural structure , here the meanders of the river channel and the vegetation . another strategy is bioremediation , which recruits organisms temporarily to help remove toxins , like bacteria that eat wastes or plants that leach out metals from tainted soils . some kinds of fungi and bacteria are even being explored as ways to bioremediate oil spills . yet another , somewhat more invasive , restoration method is biological augmentation . rather than removing harmful substances , this involves adding organisms to the ecosystem to restore materials that are gone . plants that help fix nitrogen , like beans , acacia trees , and lupine , are often used to replenish nitrogen in soils that have been damaged by things like mining or overfarming . and ecologists sometimes add mycorrhizal fungi to help new plantings like native grass take hold . but of course , we 're just humans , and we 're not as smart as millions of years of evolution . sometimes we get things wrong . for example , when you bring an invasive species into a place to eradicate another invasive species . sometimes you just end up with two invasive species on your hands , which collapses the ecosystem even more rapidly . the introduction of cane toads to australia in the 1930s to control beetles is a particularly infamous example . not only are they everywhere now , but because they 're toxic , they 're poisoning native species like dingoes that try to eat them . nice . so you know what ? i have an idea . after spending the past couple of weeks talking about ecological problems , i 've come to the conclusion that it 's just easier to protect ecosystems rather than trying to fix them because we know a lot about what makes ecosystems tick . so if we spend more time trying to save them from us and our stuff , we 'll spend less time cleaning up after ourselves and running the risks of getting it wrong . because as we all know , the sad fact is uncooking bacon is impossible . but we can eat it . thank you for joining me on this quick three-month jaunt through the natural world . i hope it made you smarter , not just in terms of passing your exams , but also in terms of being a homo sapien that inhabits this planet more wisely .
|
sometimes we get things wrong . for example , when you bring an invasive species into a place to eradicate another invasive species . sometimes you just end up with two invasive species on your hands , which collapses the ecosystem even more rapidly . the introduction of cane toads to australia in the 1930s to control beetles is a particularly infamous example .
|
are there any examples of good invasive species which have benefited an ecosystem ?
|
for the past 12 weeks , we 've been investigating our living planet together , learning how it works on many levels , how populations of organisms interact , how communities thrive and ecosystems change , and how humans are wrecking the nice , perfectly functioning systems earth has been using for hundreds of thousands of years . and now it 's graduation day . this here is like the commencement speech where i talk to you about the future and our role in it and how what we 're doing to the planet is totally awful , but we 're taking steps to undo some of the damage that we 've done . so what better way to wrap up our series on ecology than by taking a look at the growing fields of conservation biology and restoration ecology . these disciplines use all the kung fu moves that we 've learned about in the past 11 weeks and apply them to protecting ecosystems and cleaning up the messes that we 've already made . and one of the main things they teach us is that doing these things is difficult , like in the way that uncooking bacon is difficult . so let 's look at what we 're doing and try to uncook this unbelievably large pile of bacon we 've made . just outside of missoula , montana , where i live , we 've got a superfund site . not super-fun . superfund , a hazardous waste site that the government is in charge of cleaning up . the mess here was made more than 100 years ago , when there was a dam in the clark fork river behind me called the milltown dam . this part of montana has a long history of copper mining , and back in 1908 , there was a humongous flood that washed about 4.5 million cubic meters of mine tailings chock full of arsenic and toxic heavy metals into the clark fork river . and most of it washed into the reservoir created by the milltown dam . i mean , actually it was lucky that the dam was there -- it had only been completed six months before -- or the whole river system all the way to the pacific ocean would have been a toxic mess . as it happened , though , only about 160 kilometers of the river was all toxic , messed up . a lot of it recuperated over time . but all that nasty hazardous waste was still sitting behind milltown dam . and some of it leached into the groundwater that started polluting nearby residents ' wells . so scientists spent decades studying the extent of the damage caused by the waste and coming up with ways to fix it . and from 2006 to 2010 , engineers carefully removed all the toxic sediment as well as the dam itself . now this stretch of the clark fork river runs unimpeded for the first time in over a century , and the restored area where the dam used to be is being turned into a state park . efforts like this show us conservation biology and restoration ecology in action . conservation biology involves measuring the biodiversity of an ecosystem and determining how to protect it . in this case , it was used to size up the health of fish populations in the clark fork river , which were severely affected by the waste behind the dam , and the damn blocking their access to spawning grounds upstream , and figuring out how to protect them during the dam 's removal . restoration ecology , meanwhile , is the science of restoring broken ecosystems , like taking an interrupted , polluted river and turning it into what you see taking shape here . these do-gooder , fix-it-up sciences are practical rather than theoretical , by which i mean in order to fix something that 's broken , you 've got to have a good idea of what 's making it work to begin with . if something goes wrong with the expansion of the universe , we would n't be able to fix it because we have no idea at all what 's making all that happen . so in order to fix a failing ecosystem , you have to figure out what was holding it together in the first place . and the glue that holds every ecosystem together is biodiversity . but then , of course , biodiversity can mean many different things . so far , we 've generally used it to mean species diversity , or the variety of species in an ecosystem . but there are also other ways of talking about biodiversity that help conservation biologists and restoration ecologists figure out how to save species and repair ecosystems . in addition to diversity of species , ecologists look at genetic diversity within a species , as a whole and between populations . genetic diversity is important because it makes evolution possible by allowing a species to adapt to new situations like disease and climate change . and then another level of biodiversity has to do with ecosystem diversity , or the variety of different ecosystems within an area . a big , old forest , for example , can host several different kinds of ecosystems , like wetland , alpine , and aquatic ones . just like we talked about when we covered ecological succession , the more little pockets you 've got performing different functions , the more resilient the region will be as a whole . so , yeah . understanding all of this is really important to figuring out how to repair an ecosystem that is in shambles . but how do conservation biologists take the information about what makes an ecosystem tick and use it to save the place from going under ? well , there 's more than one way to approach this problem . one way is called small population conservation . this approach focuses on identifying species and populations that are really small , and tries to help boost their numbers and genetic diversity . low population and low genetic diversity are kind of a death knell for a species . they actually feed off each other , one problem making the other problem worse , ultimately causing a species to spiral into extinction . see , when a tiny little population suffers from inbreeding or genetic drift , that is , a shift in its overall genetic makeup , this leads to even less diversity , which in turn causes lower reproduction rates and higher mortality rates , which makes the population smaller still . this terrible little dynamic is known by the awesome term extinction vortex . the next step is to figure out how small a population is too small . ecologists do this by calculating what 's called the minimum viable population , which is the smallest size at which a population can survive and sustain itself . to get at this number , you have to know the real breeding population of , say , grizzly bears in yellowstone national park . and then you figure out everything you can about a grizzly 's life history , how long they live , who gets to breed the most , how often they can have babies , that kind of thing . after all that information is collected , ecologists can run the numbers and figure out that , for the grizzlies in yellowstone , a population of , say hypothetically , 90 bears would have about a 95 % chance of surviving for 100 years . but if there were a population of 100 bears , the population would likely be able to survive for 200 years . something to note , ecology involves a lot of math . so if you 're interested in this , that 's just the way it is . so that 's the small population approach to conservation . another way of preserving biodiversity focuses on populations whose numbers are in decline , no matter how large the original population was . this is known as declining population conservation , and it involves answering a series of related questions that get at the root of what 's causing an organism 's numbers to nosedive . first , you have to determine whether the population 's actually declining . then you have to figure out how big the population historically was and what its requirements were . and finally , you have to get at what 's causing the decline and figure out how to address it . milltown dam actually gives us a good example of this process . in the winter of 1996 , authorities had to release some of the water behind the dam as an emergency measure because of a big ice floe in the river that was threatening to break the dam . but when they released the water , a bunch of toxic sediment went with it , which raised the copper concentrations downriver to almost 43 times what state standards allowed . as a result , it 's estimated that about half of the fish downstream died . half of the fish , dead . and researchers have been monitoring the decline in populations ever since . this information was really helpful in determining what to do with the dam because we knew what the fish population was like before and after the release of the sediment . it was decided that it would be best to get the dam out as soon as possible rather than risk another 1996 scenario . which brings me to the place where conservation biology and restoration ecology intersect . restoration ecology is kind of where the rubber meets the road in conservation biology . it comes up with possible solutions for ecological problems . now , short of a time machine , which i 'm working on , you ca n't really get a natural environment exactly the way that it used to be . but you can at least get rid of whatever is causing the problem , and help recreate some of the elements that the ecosystem needs to function properly . all of this involves a whole suite of strategies . for instance , what 's happening in milltown is an example of structural restoration , basically the removal and cleanup of whatever human impact was causing the problem , in this case , the dam and the toxic sediments behind it . and then the rebuilding of the historical natural structure , here the meanders of the river channel and the vegetation . another strategy is bioremediation , which recruits organisms temporarily to help remove toxins , like bacteria that eat wastes or plants that leach out metals from tainted soils . some kinds of fungi and bacteria are even being explored as ways to bioremediate oil spills . yet another , somewhat more invasive , restoration method is biological augmentation . rather than removing harmful substances , this involves adding organisms to the ecosystem to restore materials that are gone . plants that help fix nitrogen , like beans , acacia trees , and lupine , are often used to replenish nitrogen in soils that have been damaged by things like mining or overfarming . and ecologists sometimes add mycorrhizal fungi to help new plantings like native grass take hold . but of course , we 're just humans , and we 're not as smart as millions of years of evolution . sometimes we get things wrong . for example , when you bring an invasive species into a place to eradicate another invasive species . sometimes you just end up with two invasive species on your hands , which collapses the ecosystem even more rapidly . the introduction of cane toads to australia in the 1930s to control beetles is a particularly infamous example . not only are they everywhere now , but because they 're toxic , they 're poisoning native species like dingoes that try to eat them . nice . so you know what ? i have an idea . after spending the past couple of weeks talking about ecological problems , i 've come to the conclusion that it 's just easier to protect ecosystems rather than trying to fix them because we know a lot about what makes ecosystems tick . so if we spend more time trying to save them from us and our stuff , we 'll spend less time cleaning up after ourselves and running the risks of getting it wrong . because as we all know , the sad fact is uncooking bacon is impossible . but we can eat it . thank you for joining me on this quick three-month jaunt through the natural world . i hope it made you smarter , not just in terms of passing your exams , but also in terms of being a homo sapien that inhabits this planet more wisely .
|
but if there were a population of 100 bears , the population would likely be able to survive for 200 years . something to note , ecology involves a lot of math . so if you 're interested in this , that 's just the way it is .
|
and , on an unrelated side note , is there a bacteria/archae/protist that is capable of turning co2 into oxygen and organic carbon ?
|
for the past 12 weeks , we 've been investigating our living planet together , learning how it works on many levels , how populations of organisms interact , how communities thrive and ecosystems change , and how humans are wrecking the nice , perfectly functioning systems earth has been using for hundreds of thousands of years . and now it 's graduation day . this here is like the commencement speech where i talk to you about the future and our role in it and how what we 're doing to the planet is totally awful , but we 're taking steps to undo some of the damage that we 've done . so what better way to wrap up our series on ecology than by taking a look at the growing fields of conservation biology and restoration ecology . these disciplines use all the kung fu moves that we 've learned about in the past 11 weeks and apply them to protecting ecosystems and cleaning up the messes that we 've already made . and one of the main things they teach us is that doing these things is difficult , like in the way that uncooking bacon is difficult . so let 's look at what we 're doing and try to uncook this unbelievably large pile of bacon we 've made . just outside of missoula , montana , where i live , we 've got a superfund site . not super-fun . superfund , a hazardous waste site that the government is in charge of cleaning up . the mess here was made more than 100 years ago , when there was a dam in the clark fork river behind me called the milltown dam . this part of montana has a long history of copper mining , and back in 1908 , there was a humongous flood that washed about 4.5 million cubic meters of mine tailings chock full of arsenic and toxic heavy metals into the clark fork river . and most of it washed into the reservoir created by the milltown dam . i mean , actually it was lucky that the dam was there -- it had only been completed six months before -- or the whole river system all the way to the pacific ocean would have been a toxic mess . as it happened , though , only about 160 kilometers of the river was all toxic , messed up . a lot of it recuperated over time . but all that nasty hazardous waste was still sitting behind milltown dam . and some of it leached into the groundwater that started polluting nearby residents ' wells . so scientists spent decades studying the extent of the damage caused by the waste and coming up with ways to fix it . and from 2006 to 2010 , engineers carefully removed all the toxic sediment as well as the dam itself . now this stretch of the clark fork river runs unimpeded for the first time in over a century , and the restored area where the dam used to be is being turned into a state park . efforts like this show us conservation biology and restoration ecology in action . conservation biology involves measuring the biodiversity of an ecosystem and determining how to protect it . in this case , it was used to size up the health of fish populations in the clark fork river , which were severely affected by the waste behind the dam , and the damn blocking their access to spawning grounds upstream , and figuring out how to protect them during the dam 's removal . restoration ecology , meanwhile , is the science of restoring broken ecosystems , like taking an interrupted , polluted river and turning it into what you see taking shape here . these do-gooder , fix-it-up sciences are practical rather than theoretical , by which i mean in order to fix something that 's broken , you 've got to have a good idea of what 's making it work to begin with . if something goes wrong with the expansion of the universe , we would n't be able to fix it because we have no idea at all what 's making all that happen . so in order to fix a failing ecosystem , you have to figure out what was holding it together in the first place . and the glue that holds every ecosystem together is biodiversity . but then , of course , biodiversity can mean many different things . so far , we 've generally used it to mean species diversity , or the variety of species in an ecosystem . but there are also other ways of talking about biodiversity that help conservation biologists and restoration ecologists figure out how to save species and repair ecosystems . in addition to diversity of species , ecologists look at genetic diversity within a species , as a whole and between populations . genetic diversity is important because it makes evolution possible by allowing a species to adapt to new situations like disease and climate change . and then another level of biodiversity has to do with ecosystem diversity , or the variety of different ecosystems within an area . a big , old forest , for example , can host several different kinds of ecosystems , like wetland , alpine , and aquatic ones . just like we talked about when we covered ecological succession , the more little pockets you 've got performing different functions , the more resilient the region will be as a whole . so , yeah . understanding all of this is really important to figuring out how to repair an ecosystem that is in shambles . but how do conservation biologists take the information about what makes an ecosystem tick and use it to save the place from going under ? well , there 's more than one way to approach this problem . one way is called small population conservation . this approach focuses on identifying species and populations that are really small , and tries to help boost their numbers and genetic diversity . low population and low genetic diversity are kind of a death knell for a species . they actually feed off each other , one problem making the other problem worse , ultimately causing a species to spiral into extinction . see , when a tiny little population suffers from inbreeding or genetic drift , that is , a shift in its overall genetic makeup , this leads to even less diversity , which in turn causes lower reproduction rates and higher mortality rates , which makes the population smaller still . this terrible little dynamic is known by the awesome term extinction vortex . the next step is to figure out how small a population is too small . ecologists do this by calculating what 's called the minimum viable population , which is the smallest size at which a population can survive and sustain itself . to get at this number , you have to know the real breeding population of , say , grizzly bears in yellowstone national park . and then you figure out everything you can about a grizzly 's life history , how long they live , who gets to breed the most , how often they can have babies , that kind of thing . after all that information is collected , ecologists can run the numbers and figure out that , for the grizzlies in yellowstone , a population of , say hypothetically , 90 bears would have about a 95 % chance of surviving for 100 years . but if there were a population of 100 bears , the population would likely be able to survive for 200 years . something to note , ecology involves a lot of math . so if you 're interested in this , that 's just the way it is . so that 's the small population approach to conservation . another way of preserving biodiversity focuses on populations whose numbers are in decline , no matter how large the original population was . this is known as declining population conservation , and it involves answering a series of related questions that get at the root of what 's causing an organism 's numbers to nosedive . first , you have to determine whether the population 's actually declining . then you have to figure out how big the population historically was and what its requirements were . and finally , you have to get at what 's causing the decline and figure out how to address it . milltown dam actually gives us a good example of this process . in the winter of 1996 , authorities had to release some of the water behind the dam as an emergency measure because of a big ice floe in the river that was threatening to break the dam . but when they released the water , a bunch of toxic sediment went with it , which raised the copper concentrations downriver to almost 43 times what state standards allowed . as a result , it 's estimated that about half of the fish downstream died . half of the fish , dead . and researchers have been monitoring the decline in populations ever since . this information was really helpful in determining what to do with the dam because we knew what the fish population was like before and after the release of the sediment . it was decided that it would be best to get the dam out as soon as possible rather than risk another 1996 scenario . which brings me to the place where conservation biology and restoration ecology intersect . restoration ecology is kind of where the rubber meets the road in conservation biology . it comes up with possible solutions for ecological problems . now , short of a time machine , which i 'm working on , you ca n't really get a natural environment exactly the way that it used to be . but you can at least get rid of whatever is causing the problem , and help recreate some of the elements that the ecosystem needs to function properly . all of this involves a whole suite of strategies . for instance , what 's happening in milltown is an example of structural restoration , basically the removal and cleanup of whatever human impact was causing the problem , in this case , the dam and the toxic sediments behind it . and then the rebuilding of the historical natural structure , here the meanders of the river channel and the vegetation . another strategy is bioremediation , which recruits organisms temporarily to help remove toxins , like bacteria that eat wastes or plants that leach out metals from tainted soils . some kinds of fungi and bacteria are even being explored as ways to bioremediate oil spills . yet another , somewhat more invasive , restoration method is biological augmentation . rather than removing harmful substances , this involves adding organisms to the ecosystem to restore materials that are gone . plants that help fix nitrogen , like beans , acacia trees , and lupine , are often used to replenish nitrogen in soils that have been damaged by things like mining or overfarming . and ecologists sometimes add mycorrhizal fungi to help new plantings like native grass take hold . but of course , we 're just humans , and we 're not as smart as millions of years of evolution . sometimes we get things wrong . for example , when you bring an invasive species into a place to eradicate another invasive species . sometimes you just end up with two invasive species on your hands , which collapses the ecosystem even more rapidly . the introduction of cane toads to australia in the 1930s to control beetles is a particularly infamous example . not only are they everywhere now , but because they 're toxic , they 're poisoning native species like dingoes that try to eat them . nice . so you know what ? i have an idea . after spending the past couple of weeks talking about ecological problems , i 've come to the conclusion that it 's just easier to protect ecosystems rather than trying to fix them because we know a lot about what makes ecosystems tick . so if we spend more time trying to save them from us and our stuff , we 'll spend less time cleaning up after ourselves and running the risks of getting it wrong . because as we all know , the sad fact is uncooking bacon is impossible . but we can eat it . thank you for joining me on this quick three-month jaunt through the natural world . i hope it made you smarter , not just in terms of passing your exams , but also in terms of being a homo sapien that inhabits this planet more wisely .
|
now this stretch of the clark fork river runs unimpeded for the first time in over a century , and the restored area where the dam used to be is being turned into a state park . efforts like this show us conservation biology and restoration ecology in action . conservation biology involves measuring the biodiversity of an ecosystem and determining how to protect it .
|
can someone please explain the difference between conservation and restoration ecology along with some examples ?
|
for the past 12 weeks , we 've been investigating our living planet together , learning how it works on many levels , how populations of organisms interact , how communities thrive and ecosystems change , and how humans are wrecking the nice , perfectly functioning systems earth has been using for hundreds of thousands of years . and now it 's graduation day . this here is like the commencement speech where i talk to you about the future and our role in it and how what we 're doing to the planet is totally awful , but we 're taking steps to undo some of the damage that we 've done . so what better way to wrap up our series on ecology than by taking a look at the growing fields of conservation biology and restoration ecology . these disciplines use all the kung fu moves that we 've learned about in the past 11 weeks and apply them to protecting ecosystems and cleaning up the messes that we 've already made . and one of the main things they teach us is that doing these things is difficult , like in the way that uncooking bacon is difficult . so let 's look at what we 're doing and try to uncook this unbelievably large pile of bacon we 've made . just outside of missoula , montana , where i live , we 've got a superfund site . not super-fun . superfund , a hazardous waste site that the government is in charge of cleaning up . the mess here was made more than 100 years ago , when there was a dam in the clark fork river behind me called the milltown dam . this part of montana has a long history of copper mining , and back in 1908 , there was a humongous flood that washed about 4.5 million cubic meters of mine tailings chock full of arsenic and toxic heavy metals into the clark fork river . and most of it washed into the reservoir created by the milltown dam . i mean , actually it was lucky that the dam was there -- it had only been completed six months before -- or the whole river system all the way to the pacific ocean would have been a toxic mess . as it happened , though , only about 160 kilometers of the river was all toxic , messed up . a lot of it recuperated over time . but all that nasty hazardous waste was still sitting behind milltown dam . and some of it leached into the groundwater that started polluting nearby residents ' wells . so scientists spent decades studying the extent of the damage caused by the waste and coming up with ways to fix it . and from 2006 to 2010 , engineers carefully removed all the toxic sediment as well as the dam itself . now this stretch of the clark fork river runs unimpeded for the first time in over a century , and the restored area where the dam used to be is being turned into a state park . efforts like this show us conservation biology and restoration ecology in action . conservation biology involves measuring the biodiversity of an ecosystem and determining how to protect it . in this case , it was used to size up the health of fish populations in the clark fork river , which were severely affected by the waste behind the dam , and the damn blocking their access to spawning grounds upstream , and figuring out how to protect them during the dam 's removal . restoration ecology , meanwhile , is the science of restoring broken ecosystems , like taking an interrupted , polluted river and turning it into what you see taking shape here . these do-gooder , fix-it-up sciences are practical rather than theoretical , by which i mean in order to fix something that 's broken , you 've got to have a good idea of what 's making it work to begin with . if something goes wrong with the expansion of the universe , we would n't be able to fix it because we have no idea at all what 's making all that happen . so in order to fix a failing ecosystem , you have to figure out what was holding it together in the first place . and the glue that holds every ecosystem together is biodiversity . but then , of course , biodiversity can mean many different things . so far , we 've generally used it to mean species diversity , or the variety of species in an ecosystem . but there are also other ways of talking about biodiversity that help conservation biologists and restoration ecologists figure out how to save species and repair ecosystems . in addition to diversity of species , ecologists look at genetic diversity within a species , as a whole and between populations . genetic diversity is important because it makes evolution possible by allowing a species to adapt to new situations like disease and climate change . and then another level of biodiversity has to do with ecosystem diversity , or the variety of different ecosystems within an area . a big , old forest , for example , can host several different kinds of ecosystems , like wetland , alpine , and aquatic ones . just like we talked about when we covered ecological succession , the more little pockets you 've got performing different functions , the more resilient the region will be as a whole . so , yeah . understanding all of this is really important to figuring out how to repair an ecosystem that is in shambles . but how do conservation biologists take the information about what makes an ecosystem tick and use it to save the place from going under ? well , there 's more than one way to approach this problem . one way is called small population conservation . this approach focuses on identifying species and populations that are really small , and tries to help boost their numbers and genetic diversity . low population and low genetic diversity are kind of a death knell for a species . they actually feed off each other , one problem making the other problem worse , ultimately causing a species to spiral into extinction . see , when a tiny little population suffers from inbreeding or genetic drift , that is , a shift in its overall genetic makeup , this leads to even less diversity , which in turn causes lower reproduction rates and higher mortality rates , which makes the population smaller still . this terrible little dynamic is known by the awesome term extinction vortex . the next step is to figure out how small a population is too small . ecologists do this by calculating what 's called the minimum viable population , which is the smallest size at which a population can survive and sustain itself . to get at this number , you have to know the real breeding population of , say , grizzly bears in yellowstone national park . and then you figure out everything you can about a grizzly 's life history , how long they live , who gets to breed the most , how often they can have babies , that kind of thing . after all that information is collected , ecologists can run the numbers and figure out that , for the grizzlies in yellowstone , a population of , say hypothetically , 90 bears would have about a 95 % chance of surviving for 100 years . but if there were a population of 100 bears , the population would likely be able to survive for 200 years . something to note , ecology involves a lot of math . so if you 're interested in this , that 's just the way it is . so that 's the small population approach to conservation . another way of preserving biodiversity focuses on populations whose numbers are in decline , no matter how large the original population was . this is known as declining population conservation , and it involves answering a series of related questions that get at the root of what 's causing an organism 's numbers to nosedive . first , you have to determine whether the population 's actually declining . then you have to figure out how big the population historically was and what its requirements were . and finally , you have to get at what 's causing the decline and figure out how to address it . milltown dam actually gives us a good example of this process . in the winter of 1996 , authorities had to release some of the water behind the dam as an emergency measure because of a big ice floe in the river that was threatening to break the dam . but when they released the water , a bunch of toxic sediment went with it , which raised the copper concentrations downriver to almost 43 times what state standards allowed . as a result , it 's estimated that about half of the fish downstream died . half of the fish , dead . and researchers have been monitoring the decline in populations ever since . this information was really helpful in determining what to do with the dam because we knew what the fish population was like before and after the release of the sediment . it was decided that it would be best to get the dam out as soon as possible rather than risk another 1996 scenario . which brings me to the place where conservation biology and restoration ecology intersect . restoration ecology is kind of where the rubber meets the road in conservation biology . it comes up with possible solutions for ecological problems . now , short of a time machine , which i 'm working on , you ca n't really get a natural environment exactly the way that it used to be . but you can at least get rid of whatever is causing the problem , and help recreate some of the elements that the ecosystem needs to function properly . all of this involves a whole suite of strategies . for instance , what 's happening in milltown is an example of structural restoration , basically the removal and cleanup of whatever human impact was causing the problem , in this case , the dam and the toxic sediments behind it . and then the rebuilding of the historical natural structure , here the meanders of the river channel and the vegetation . another strategy is bioremediation , which recruits organisms temporarily to help remove toxins , like bacteria that eat wastes or plants that leach out metals from tainted soils . some kinds of fungi and bacteria are even being explored as ways to bioremediate oil spills . yet another , somewhat more invasive , restoration method is biological augmentation . rather than removing harmful substances , this involves adding organisms to the ecosystem to restore materials that are gone . plants that help fix nitrogen , like beans , acacia trees , and lupine , are often used to replenish nitrogen in soils that have been damaged by things like mining or overfarming . and ecologists sometimes add mycorrhizal fungi to help new plantings like native grass take hold . but of course , we 're just humans , and we 're not as smart as millions of years of evolution . sometimes we get things wrong . for example , when you bring an invasive species into a place to eradicate another invasive species . sometimes you just end up with two invasive species on your hands , which collapses the ecosystem even more rapidly . the introduction of cane toads to australia in the 1930s to control beetles is a particularly infamous example . not only are they everywhere now , but because they 're toxic , they 're poisoning native species like dingoes that try to eat them . nice . so you know what ? i have an idea . after spending the past couple of weeks talking about ecological problems , i 've come to the conclusion that it 's just easier to protect ecosystems rather than trying to fix them because we know a lot about what makes ecosystems tick . so if we spend more time trying to save them from us and our stuff , we 'll spend less time cleaning up after ourselves and running the risks of getting it wrong . because as we all know , the sad fact is uncooking bacon is impossible . but we can eat it . thank you for joining me on this quick three-month jaunt through the natural world . i hope it made you smarter , not just in terms of passing your exams , but also in terms of being a homo sapien that inhabits this planet more wisely .
|
now this stretch of the clark fork river runs unimpeded for the first time in over a century , and the restored area where the dam used to be is being turned into a state park . efforts like this show us conservation biology and restoration ecology in action . conservation biology involves measuring the biodiversity of an ecosystem and determining how to protect it .
|
which country is devoting , or spending the most on conservation as well as restoration ecology ?
|
for the past 12 weeks , we 've been investigating our living planet together , learning how it works on many levels , how populations of organisms interact , how communities thrive and ecosystems change , and how humans are wrecking the nice , perfectly functioning systems earth has been using for hundreds of thousands of years . and now it 's graduation day . this here is like the commencement speech where i talk to you about the future and our role in it and how what we 're doing to the planet is totally awful , but we 're taking steps to undo some of the damage that we 've done . so what better way to wrap up our series on ecology than by taking a look at the growing fields of conservation biology and restoration ecology . these disciplines use all the kung fu moves that we 've learned about in the past 11 weeks and apply them to protecting ecosystems and cleaning up the messes that we 've already made . and one of the main things they teach us is that doing these things is difficult , like in the way that uncooking bacon is difficult . so let 's look at what we 're doing and try to uncook this unbelievably large pile of bacon we 've made . just outside of missoula , montana , where i live , we 've got a superfund site . not super-fun . superfund , a hazardous waste site that the government is in charge of cleaning up . the mess here was made more than 100 years ago , when there was a dam in the clark fork river behind me called the milltown dam . this part of montana has a long history of copper mining , and back in 1908 , there was a humongous flood that washed about 4.5 million cubic meters of mine tailings chock full of arsenic and toxic heavy metals into the clark fork river . and most of it washed into the reservoir created by the milltown dam . i mean , actually it was lucky that the dam was there -- it had only been completed six months before -- or the whole river system all the way to the pacific ocean would have been a toxic mess . as it happened , though , only about 160 kilometers of the river was all toxic , messed up . a lot of it recuperated over time . but all that nasty hazardous waste was still sitting behind milltown dam . and some of it leached into the groundwater that started polluting nearby residents ' wells . so scientists spent decades studying the extent of the damage caused by the waste and coming up with ways to fix it . and from 2006 to 2010 , engineers carefully removed all the toxic sediment as well as the dam itself . now this stretch of the clark fork river runs unimpeded for the first time in over a century , and the restored area where the dam used to be is being turned into a state park . efforts like this show us conservation biology and restoration ecology in action . conservation biology involves measuring the biodiversity of an ecosystem and determining how to protect it . in this case , it was used to size up the health of fish populations in the clark fork river , which were severely affected by the waste behind the dam , and the damn blocking their access to spawning grounds upstream , and figuring out how to protect them during the dam 's removal . restoration ecology , meanwhile , is the science of restoring broken ecosystems , like taking an interrupted , polluted river and turning it into what you see taking shape here . these do-gooder , fix-it-up sciences are practical rather than theoretical , by which i mean in order to fix something that 's broken , you 've got to have a good idea of what 's making it work to begin with . if something goes wrong with the expansion of the universe , we would n't be able to fix it because we have no idea at all what 's making all that happen . so in order to fix a failing ecosystem , you have to figure out what was holding it together in the first place . and the glue that holds every ecosystem together is biodiversity . but then , of course , biodiversity can mean many different things . so far , we 've generally used it to mean species diversity , or the variety of species in an ecosystem . but there are also other ways of talking about biodiversity that help conservation biologists and restoration ecologists figure out how to save species and repair ecosystems . in addition to diversity of species , ecologists look at genetic diversity within a species , as a whole and between populations . genetic diversity is important because it makes evolution possible by allowing a species to adapt to new situations like disease and climate change . and then another level of biodiversity has to do with ecosystem diversity , or the variety of different ecosystems within an area . a big , old forest , for example , can host several different kinds of ecosystems , like wetland , alpine , and aquatic ones . just like we talked about when we covered ecological succession , the more little pockets you 've got performing different functions , the more resilient the region will be as a whole . so , yeah . understanding all of this is really important to figuring out how to repair an ecosystem that is in shambles . but how do conservation biologists take the information about what makes an ecosystem tick and use it to save the place from going under ? well , there 's more than one way to approach this problem . one way is called small population conservation . this approach focuses on identifying species and populations that are really small , and tries to help boost their numbers and genetic diversity . low population and low genetic diversity are kind of a death knell for a species . they actually feed off each other , one problem making the other problem worse , ultimately causing a species to spiral into extinction . see , when a tiny little population suffers from inbreeding or genetic drift , that is , a shift in its overall genetic makeup , this leads to even less diversity , which in turn causes lower reproduction rates and higher mortality rates , which makes the population smaller still . this terrible little dynamic is known by the awesome term extinction vortex . the next step is to figure out how small a population is too small . ecologists do this by calculating what 's called the minimum viable population , which is the smallest size at which a population can survive and sustain itself . to get at this number , you have to know the real breeding population of , say , grizzly bears in yellowstone national park . and then you figure out everything you can about a grizzly 's life history , how long they live , who gets to breed the most , how often they can have babies , that kind of thing . after all that information is collected , ecologists can run the numbers and figure out that , for the grizzlies in yellowstone , a population of , say hypothetically , 90 bears would have about a 95 % chance of surviving for 100 years . but if there were a population of 100 bears , the population would likely be able to survive for 200 years . something to note , ecology involves a lot of math . so if you 're interested in this , that 's just the way it is . so that 's the small population approach to conservation . another way of preserving biodiversity focuses on populations whose numbers are in decline , no matter how large the original population was . this is known as declining population conservation , and it involves answering a series of related questions that get at the root of what 's causing an organism 's numbers to nosedive . first , you have to determine whether the population 's actually declining . then you have to figure out how big the population historically was and what its requirements were . and finally , you have to get at what 's causing the decline and figure out how to address it . milltown dam actually gives us a good example of this process . in the winter of 1996 , authorities had to release some of the water behind the dam as an emergency measure because of a big ice floe in the river that was threatening to break the dam . but when they released the water , a bunch of toxic sediment went with it , which raised the copper concentrations downriver to almost 43 times what state standards allowed . as a result , it 's estimated that about half of the fish downstream died . half of the fish , dead . and researchers have been monitoring the decline in populations ever since . this information was really helpful in determining what to do with the dam because we knew what the fish population was like before and after the release of the sediment . it was decided that it would be best to get the dam out as soon as possible rather than risk another 1996 scenario . which brings me to the place where conservation biology and restoration ecology intersect . restoration ecology is kind of where the rubber meets the road in conservation biology . it comes up with possible solutions for ecological problems . now , short of a time machine , which i 'm working on , you ca n't really get a natural environment exactly the way that it used to be . but you can at least get rid of whatever is causing the problem , and help recreate some of the elements that the ecosystem needs to function properly . all of this involves a whole suite of strategies . for instance , what 's happening in milltown is an example of structural restoration , basically the removal and cleanup of whatever human impact was causing the problem , in this case , the dam and the toxic sediments behind it . and then the rebuilding of the historical natural structure , here the meanders of the river channel and the vegetation . another strategy is bioremediation , which recruits organisms temporarily to help remove toxins , like bacteria that eat wastes or plants that leach out metals from tainted soils . some kinds of fungi and bacteria are even being explored as ways to bioremediate oil spills . yet another , somewhat more invasive , restoration method is biological augmentation . rather than removing harmful substances , this involves adding organisms to the ecosystem to restore materials that are gone . plants that help fix nitrogen , like beans , acacia trees , and lupine , are often used to replenish nitrogen in soils that have been damaged by things like mining or overfarming . and ecologists sometimes add mycorrhizal fungi to help new plantings like native grass take hold . but of course , we 're just humans , and we 're not as smart as millions of years of evolution . sometimes we get things wrong . for example , when you bring an invasive species into a place to eradicate another invasive species . sometimes you just end up with two invasive species on your hands , which collapses the ecosystem even more rapidly . the introduction of cane toads to australia in the 1930s to control beetles is a particularly infamous example . not only are they everywhere now , but because they 're toxic , they 're poisoning native species like dingoes that try to eat them . nice . so you know what ? i have an idea . after spending the past couple of weeks talking about ecological problems , i 've come to the conclusion that it 's just easier to protect ecosystems rather than trying to fix them because we know a lot about what makes ecosystems tick . so if we spend more time trying to save them from us and our stuff , we 'll spend less time cleaning up after ourselves and running the risks of getting it wrong . because as we all know , the sad fact is uncooking bacon is impossible . but we can eat it . thank you for joining me on this quick three-month jaunt through the natural world . i hope it made you smarter , not just in terms of passing your exams , but also in terms of being a homo sapien that inhabits this planet more wisely .
|
and most of it washed into the reservoir created by the milltown dam . i mean , actually it was lucky that the dam was there -- it had only been completed six months before -- or the whole river system all the way to the pacific ocean would have been a toxic mess . as it happened , though , only about 160 kilometers of the river was all toxic , messed up .
|
0 would n't getting the dam out of the way release the rest of the toxic copper sediments ?
|
for the past 12 weeks , we 've been investigating our living planet together , learning how it works on many levels , how populations of organisms interact , how communities thrive and ecosystems change , and how humans are wrecking the nice , perfectly functioning systems earth has been using for hundreds of thousands of years . and now it 's graduation day . this here is like the commencement speech where i talk to you about the future and our role in it and how what we 're doing to the planet is totally awful , but we 're taking steps to undo some of the damage that we 've done . so what better way to wrap up our series on ecology than by taking a look at the growing fields of conservation biology and restoration ecology . these disciplines use all the kung fu moves that we 've learned about in the past 11 weeks and apply them to protecting ecosystems and cleaning up the messes that we 've already made . and one of the main things they teach us is that doing these things is difficult , like in the way that uncooking bacon is difficult . so let 's look at what we 're doing and try to uncook this unbelievably large pile of bacon we 've made . just outside of missoula , montana , where i live , we 've got a superfund site . not super-fun . superfund , a hazardous waste site that the government is in charge of cleaning up . the mess here was made more than 100 years ago , when there was a dam in the clark fork river behind me called the milltown dam . this part of montana has a long history of copper mining , and back in 1908 , there was a humongous flood that washed about 4.5 million cubic meters of mine tailings chock full of arsenic and toxic heavy metals into the clark fork river . and most of it washed into the reservoir created by the milltown dam . i mean , actually it was lucky that the dam was there -- it had only been completed six months before -- or the whole river system all the way to the pacific ocean would have been a toxic mess . as it happened , though , only about 160 kilometers of the river was all toxic , messed up . a lot of it recuperated over time . but all that nasty hazardous waste was still sitting behind milltown dam . and some of it leached into the groundwater that started polluting nearby residents ' wells . so scientists spent decades studying the extent of the damage caused by the waste and coming up with ways to fix it . and from 2006 to 2010 , engineers carefully removed all the toxic sediment as well as the dam itself . now this stretch of the clark fork river runs unimpeded for the first time in over a century , and the restored area where the dam used to be is being turned into a state park . efforts like this show us conservation biology and restoration ecology in action . conservation biology involves measuring the biodiversity of an ecosystem and determining how to protect it . in this case , it was used to size up the health of fish populations in the clark fork river , which were severely affected by the waste behind the dam , and the damn blocking their access to spawning grounds upstream , and figuring out how to protect them during the dam 's removal . restoration ecology , meanwhile , is the science of restoring broken ecosystems , like taking an interrupted , polluted river and turning it into what you see taking shape here . these do-gooder , fix-it-up sciences are practical rather than theoretical , by which i mean in order to fix something that 's broken , you 've got to have a good idea of what 's making it work to begin with . if something goes wrong with the expansion of the universe , we would n't be able to fix it because we have no idea at all what 's making all that happen . so in order to fix a failing ecosystem , you have to figure out what was holding it together in the first place . and the glue that holds every ecosystem together is biodiversity . but then , of course , biodiversity can mean many different things . so far , we 've generally used it to mean species diversity , or the variety of species in an ecosystem . but there are also other ways of talking about biodiversity that help conservation biologists and restoration ecologists figure out how to save species and repair ecosystems . in addition to diversity of species , ecologists look at genetic diversity within a species , as a whole and between populations . genetic diversity is important because it makes evolution possible by allowing a species to adapt to new situations like disease and climate change . and then another level of biodiversity has to do with ecosystem diversity , or the variety of different ecosystems within an area . a big , old forest , for example , can host several different kinds of ecosystems , like wetland , alpine , and aquatic ones . just like we talked about when we covered ecological succession , the more little pockets you 've got performing different functions , the more resilient the region will be as a whole . so , yeah . understanding all of this is really important to figuring out how to repair an ecosystem that is in shambles . but how do conservation biologists take the information about what makes an ecosystem tick and use it to save the place from going under ? well , there 's more than one way to approach this problem . one way is called small population conservation . this approach focuses on identifying species and populations that are really small , and tries to help boost their numbers and genetic diversity . low population and low genetic diversity are kind of a death knell for a species . they actually feed off each other , one problem making the other problem worse , ultimately causing a species to spiral into extinction . see , when a tiny little population suffers from inbreeding or genetic drift , that is , a shift in its overall genetic makeup , this leads to even less diversity , which in turn causes lower reproduction rates and higher mortality rates , which makes the population smaller still . this terrible little dynamic is known by the awesome term extinction vortex . the next step is to figure out how small a population is too small . ecologists do this by calculating what 's called the minimum viable population , which is the smallest size at which a population can survive and sustain itself . to get at this number , you have to know the real breeding population of , say , grizzly bears in yellowstone national park . and then you figure out everything you can about a grizzly 's life history , how long they live , who gets to breed the most , how often they can have babies , that kind of thing . after all that information is collected , ecologists can run the numbers and figure out that , for the grizzlies in yellowstone , a population of , say hypothetically , 90 bears would have about a 95 % chance of surviving for 100 years . but if there were a population of 100 bears , the population would likely be able to survive for 200 years . something to note , ecology involves a lot of math . so if you 're interested in this , that 's just the way it is . so that 's the small population approach to conservation . another way of preserving biodiversity focuses on populations whose numbers are in decline , no matter how large the original population was . this is known as declining population conservation , and it involves answering a series of related questions that get at the root of what 's causing an organism 's numbers to nosedive . first , you have to determine whether the population 's actually declining . then you have to figure out how big the population historically was and what its requirements were . and finally , you have to get at what 's causing the decline and figure out how to address it . milltown dam actually gives us a good example of this process . in the winter of 1996 , authorities had to release some of the water behind the dam as an emergency measure because of a big ice floe in the river that was threatening to break the dam . but when they released the water , a bunch of toxic sediment went with it , which raised the copper concentrations downriver to almost 43 times what state standards allowed . as a result , it 's estimated that about half of the fish downstream died . half of the fish , dead . and researchers have been monitoring the decline in populations ever since . this information was really helpful in determining what to do with the dam because we knew what the fish population was like before and after the release of the sediment . it was decided that it would be best to get the dam out as soon as possible rather than risk another 1996 scenario . which brings me to the place where conservation biology and restoration ecology intersect . restoration ecology is kind of where the rubber meets the road in conservation biology . it comes up with possible solutions for ecological problems . now , short of a time machine , which i 'm working on , you ca n't really get a natural environment exactly the way that it used to be . but you can at least get rid of whatever is causing the problem , and help recreate some of the elements that the ecosystem needs to function properly . all of this involves a whole suite of strategies . for instance , what 's happening in milltown is an example of structural restoration , basically the removal and cleanup of whatever human impact was causing the problem , in this case , the dam and the toxic sediments behind it . and then the rebuilding of the historical natural structure , here the meanders of the river channel and the vegetation . another strategy is bioremediation , which recruits organisms temporarily to help remove toxins , like bacteria that eat wastes or plants that leach out metals from tainted soils . some kinds of fungi and bacteria are even being explored as ways to bioremediate oil spills . yet another , somewhat more invasive , restoration method is biological augmentation . rather than removing harmful substances , this involves adding organisms to the ecosystem to restore materials that are gone . plants that help fix nitrogen , like beans , acacia trees , and lupine , are often used to replenish nitrogen in soils that have been damaged by things like mining or overfarming . and ecologists sometimes add mycorrhizal fungi to help new plantings like native grass take hold . but of course , we 're just humans , and we 're not as smart as millions of years of evolution . sometimes we get things wrong . for example , when you bring an invasive species into a place to eradicate another invasive species . sometimes you just end up with two invasive species on your hands , which collapses the ecosystem even more rapidly . the introduction of cane toads to australia in the 1930s to control beetles is a particularly infamous example . not only are they everywhere now , but because they 're toxic , they 're poisoning native species like dingoes that try to eat them . nice . so you know what ? i have an idea . after spending the past couple of weeks talking about ecological problems , i 've come to the conclusion that it 's just easier to protect ecosystems rather than trying to fix them because we know a lot about what makes ecosystems tick . so if we spend more time trying to save them from us and our stuff , we 'll spend less time cleaning up after ourselves and running the risks of getting it wrong . because as we all know , the sad fact is uncooking bacon is impossible . but we can eat it . thank you for joining me on this quick three-month jaunt through the natural world . i hope it made you smarter , not just in terms of passing your exams , but also in terms of being a homo sapien that inhabits this planet more wisely .
|
yet another , somewhat more invasive , restoration method is biological augmentation . rather than removing harmful substances , this involves adding organisms to the ecosystem to restore materials that are gone . plants that help fix nitrogen , like beans , acacia trees , and lupine , are often used to replenish nitrogen in soils that have been damaged by things like mining or overfarming .
|
how long does it take to restore an ecosystem ?
|
for the past 12 weeks , we 've been investigating our living planet together , learning how it works on many levels , how populations of organisms interact , how communities thrive and ecosystems change , and how humans are wrecking the nice , perfectly functioning systems earth has been using for hundreds of thousands of years . and now it 's graduation day . this here is like the commencement speech where i talk to you about the future and our role in it and how what we 're doing to the planet is totally awful , but we 're taking steps to undo some of the damage that we 've done . so what better way to wrap up our series on ecology than by taking a look at the growing fields of conservation biology and restoration ecology . these disciplines use all the kung fu moves that we 've learned about in the past 11 weeks and apply them to protecting ecosystems and cleaning up the messes that we 've already made . and one of the main things they teach us is that doing these things is difficult , like in the way that uncooking bacon is difficult . so let 's look at what we 're doing and try to uncook this unbelievably large pile of bacon we 've made . just outside of missoula , montana , where i live , we 've got a superfund site . not super-fun . superfund , a hazardous waste site that the government is in charge of cleaning up . the mess here was made more than 100 years ago , when there was a dam in the clark fork river behind me called the milltown dam . this part of montana has a long history of copper mining , and back in 1908 , there was a humongous flood that washed about 4.5 million cubic meters of mine tailings chock full of arsenic and toxic heavy metals into the clark fork river . and most of it washed into the reservoir created by the milltown dam . i mean , actually it was lucky that the dam was there -- it had only been completed six months before -- or the whole river system all the way to the pacific ocean would have been a toxic mess . as it happened , though , only about 160 kilometers of the river was all toxic , messed up . a lot of it recuperated over time . but all that nasty hazardous waste was still sitting behind milltown dam . and some of it leached into the groundwater that started polluting nearby residents ' wells . so scientists spent decades studying the extent of the damage caused by the waste and coming up with ways to fix it . and from 2006 to 2010 , engineers carefully removed all the toxic sediment as well as the dam itself . now this stretch of the clark fork river runs unimpeded for the first time in over a century , and the restored area where the dam used to be is being turned into a state park . efforts like this show us conservation biology and restoration ecology in action . conservation biology involves measuring the biodiversity of an ecosystem and determining how to protect it . in this case , it was used to size up the health of fish populations in the clark fork river , which were severely affected by the waste behind the dam , and the damn blocking their access to spawning grounds upstream , and figuring out how to protect them during the dam 's removal . restoration ecology , meanwhile , is the science of restoring broken ecosystems , like taking an interrupted , polluted river and turning it into what you see taking shape here . these do-gooder , fix-it-up sciences are practical rather than theoretical , by which i mean in order to fix something that 's broken , you 've got to have a good idea of what 's making it work to begin with . if something goes wrong with the expansion of the universe , we would n't be able to fix it because we have no idea at all what 's making all that happen . so in order to fix a failing ecosystem , you have to figure out what was holding it together in the first place . and the glue that holds every ecosystem together is biodiversity . but then , of course , biodiversity can mean many different things . so far , we 've generally used it to mean species diversity , or the variety of species in an ecosystem . but there are also other ways of talking about biodiversity that help conservation biologists and restoration ecologists figure out how to save species and repair ecosystems . in addition to diversity of species , ecologists look at genetic diversity within a species , as a whole and between populations . genetic diversity is important because it makes evolution possible by allowing a species to adapt to new situations like disease and climate change . and then another level of biodiversity has to do with ecosystem diversity , or the variety of different ecosystems within an area . a big , old forest , for example , can host several different kinds of ecosystems , like wetland , alpine , and aquatic ones . just like we talked about when we covered ecological succession , the more little pockets you 've got performing different functions , the more resilient the region will be as a whole . so , yeah . understanding all of this is really important to figuring out how to repair an ecosystem that is in shambles . but how do conservation biologists take the information about what makes an ecosystem tick and use it to save the place from going under ? well , there 's more than one way to approach this problem . one way is called small population conservation . this approach focuses on identifying species and populations that are really small , and tries to help boost their numbers and genetic diversity . low population and low genetic diversity are kind of a death knell for a species . they actually feed off each other , one problem making the other problem worse , ultimately causing a species to spiral into extinction . see , when a tiny little population suffers from inbreeding or genetic drift , that is , a shift in its overall genetic makeup , this leads to even less diversity , which in turn causes lower reproduction rates and higher mortality rates , which makes the population smaller still . this terrible little dynamic is known by the awesome term extinction vortex . the next step is to figure out how small a population is too small . ecologists do this by calculating what 's called the minimum viable population , which is the smallest size at which a population can survive and sustain itself . to get at this number , you have to know the real breeding population of , say , grizzly bears in yellowstone national park . and then you figure out everything you can about a grizzly 's life history , how long they live , who gets to breed the most , how often they can have babies , that kind of thing . after all that information is collected , ecologists can run the numbers and figure out that , for the grizzlies in yellowstone , a population of , say hypothetically , 90 bears would have about a 95 % chance of surviving for 100 years . but if there were a population of 100 bears , the population would likely be able to survive for 200 years . something to note , ecology involves a lot of math . so if you 're interested in this , that 's just the way it is . so that 's the small population approach to conservation . another way of preserving biodiversity focuses on populations whose numbers are in decline , no matter how large the original population was . this is known as declining population conservation , and it involves answering a series of related questions that get at the root of what 's causing an organism 's numbers to nosedive . first , you have to determine whether the population 's actually declining . then you have to figure out how big the population historically was and what its requirements were . and finally , you have to get at what 's causing the decline and figure out how to address it . milltown dam actually gives us a good example of this process . in the winter of 1996 , authorities had to release some of the water behind the dam as an emergency measure because of a big ice floe in the river that was threatening to break the dam . but when they released the water , a bunch of toxic sediment went with it , which raised the copper concentrations downriver to almost 43 times what state standards allowed . as a result , it 's estimated that about half of the fish downstream died . half of the fish , dead . and researchers have been monitoring the decline in populations ever since . this information was really helpful in determining what to do with the dam because we knew what the fish population was like before and after the release of the sediment . it was decided that it would be best to get the dam out as soon as possible rather than risk another 1996 scenario . which brings me to the place where conservation biology and restoration ecology intersect . restoration ecology is kind of where the rubber meets the road in conservation biology . it comes up with possible solutions for ecological problems . now , short of a time machine , which i 'm working on , you ca n't really get a natural environment exactly the way that it used to be . but you can at least get rid of whatever is causing the problem , and help recreate some of the elements that the ecosystem needs to function properly . all of this involves a whole suite of strategies . for instance , what 's happening in milltown is an example of structural restoration , basically the removal and cleanup of whatever human impact was causing the problem , in this case , the dam and the toxic sediments behind it . and then the rebuilding of the historical natural structure , here the meanders of the river channel and the vegetation . another strategy is bioremediation , which recruits organisms temporarily to help remove toxins , like bacteria that eat wastes or plants that leach out metals from tainted soils . some kinds of fungi and bacteria are even being explored as ways to bioremediate oil spills . yet another , somewhat more invasive , restoration method is biological augmentation . rather than removing harmful substances , this involves adding organisms to the ecosystem to restore materials that are gone . plants that help fix nitrogen , like beans , acacia trees , and lupine , are often used to replenish nitrogen in soils that have been damaged by things like mining or overfarming . and ecologists sometimes add mycorrhizal fungi to help new plantings like native grass take hold . but of course , we 're just humans , and we 're not as smart as millions of years of evolution . sometimes we get things wrong . for example , when you bring an invasive species into a place to eradicate another invasive species . sometimes you just end up with two invasive species on your hands , which collapses the ecosystem even more rapidly . the introduction of cane toads to australia in the 1930s to control beetles is a particularly infamous example . not only are they everywhere now , but because they 're toxic , they 're poisoning native species like dingoes that try to eat them . nice . so you know what ? i have an idea . after spending the past couple of weeks talking about ecological problems , i 've come to the conclusion that it 's just easier to protect ecosystems rather than trying to fix them because we know a lot about what makes ecosystems tick . so if we spend more time trying to save them from us and our stuff , we 'll spend less time cleaning up after ourselves and running the risks of getting it wrong . because as we all know , the sad fact is uncooking bacon is impossible . but we can eat it . thank you for joining me on this quick three-month jaunt through the natural world . i hope it made you smarter , not just in terms of passing your exams , but also in terms of being a homo sapien that inhabits this planet more wisely .
|
yet another , somewhat more invasive , restoration method is biological augmentation . rather than removing harmful substances , this involves adding organisms to the ecosystem to restore materials that are gone . plants that help fix nitrogen , like beans , acacia trees , and lupine , are often used to replenish nitrogen in soils that have been damaged by things like mining or overfarming .
|
what is an adaptation that organisms in the aphotic zone might have ?
|
for the past 12 weeks , we 've been investigating our living planet together , learning how it works on many levels , how populations of organisms interact , how communities thrive and ecosystems change , and how humans are wrecking the nice , perfectly functioning systems earth has been using for hundreds of thousands of years . and now it 's graduation day . this here is like the commencement speech where i talk to you about the future and our role in it and how what we 're doing to the planet is totally awful , but we 're taking steps to undo some of the damage that we 've done . so what better way to wrap up our series on ecology than by taking a look at the growing fields of conservation biology and restoration ecology . these disciplines use all the kung fu moves that we 've learned about in the past 11 weeks and apply them to protecting ecosystems and cleaning up the messes that we 've already made . and one of the main things they teach us is that doing these things is difficult , like in the way that uncooking bacon is difficult . so let 's look at what we 're doing and try to uncook this unbelievably large pile of bacon we 've made . just outside of missoula , montana , where i live , we 've got a superfund site . not super-fun . superfund , a hazardous waste site that the government is in charge of cleaning up . the mess here was made more than 100 years ago , when there was a dam in the clark fork river behind me called the milltown dam . this part of montana has a long history of copper mining , and back in 1908 , there was a humongous flood that washed about 4.5 million cubic meters of mine tailings chock full of arsenic and toxic heavy metals into the clark fork river . and most of it washed into the reservoir created by the milltown dam . i mean , actually it was lucky that the dam was there -- it had only been completed six months before -- or the whole river system all the way to the pacific ocean would have been a toxic mess . as it happened , though , only about 160 kilometers of the river was all toxic , messed up . a lot of it recuperated over time . but all that nasty hazardous waste was still sitting behind milltown dam . and some of it leached into the groundwater that started polluting nearby residents ' wells . so scientists spent decades studying the extent of the damage caused by the waste and coming up with ways to fix it . and from 2006 to 2010 , engineers carefully removed all the toxic sediment as well as the dam itself . now this stretch of the clark fork river runs unimpeded for the first time in over a century , and the restored area where the dam used to be is being turned into a state park . efforts like this show us conservation biology and restoration ecology in action . conservation biology involves measuring the biodiversity of an ecosystem and determining how to protect it . in this case , it was used to size up the health of fish populations in the clark fork river , which were severely affected by the waste behind the dam , and the damn blocking their access to spawning grounds upstream , and figuring out how to protect them during the dam 's removal . restoration ecology , meanwhile , is the science of restoring broken ecosystems , like taking an interrupted , polluted river and turning it into what you see taking shape here . these do-gooder , fix-it-up sciences are practical rather than theoretical , by which i mean in order to fix something that 's broken , you 've got to have a good idea of what 's making it work to begin with . if something goes wrong with the expansion of the universe , we would n't be able to fix it because we have no idea at all what 's making all that happen . so in order to fix a failing ecosystem , you have to figure out what was holding it together in the first place . and the glue that holds every ecosystem together is biodiversity . but then , of course , biodiversity can mean many different things . so far , we 've generally used it to mean species diversity , or the variety of species in an ecosystem . but there are also other ways of talking about biodiversity that help conservation biologists and restoration ecologists figure out how to save species and repair ecosystems . in addition to diversity of species , ecologists look at genetic diversity within a species , as a whole and between populations . genetic diversity is important because it makes evolution possible by allowing a species to adapt to new situations like disease and climate change . and then another level of biodiversity has to do with ecosystem diversity , or the variety of different ecosystems within an area . a big , old forest , for example , can host several different kinds of ecosystems , like wetland , alpine , and aquatic ones . just like we talked about when we covered ecological succession , the more little pockets you 've got performing different functions , the more resilient the region will be as a whole . so , yeah . understanding all of this is really important to figuring out how to repair an ecosystem that is in shambles . but how do conservation biologists take the information about what makes an ecosystem tick and use it to save the place from going under ? well , there 's more than one way to approach this problem . one way is called small population conservation . this approach focuses on identifying species and populations that are really small , and tries to help boost their numbers and genetic diversity . low population and low genetic diversity are kind of a death knell for a species . they actually feed off each other , one problem making the other problem worse , ultimately causing a species to spiral into extinction . see , when a tiny little population suffers from inbreeding or genetic drift , that is , a shift in its overall genetic makeup , this leads to even less diversity , which in turn causes lower reproduction rates and higher mortality rates , which makes the population smaller still . this terrible little dynamic is known by the awesome term extinction vortex . the next step is to figure out how small a population is too small . ecologists do this by calculating what 's called the minimum viable population , which is the smallest size at which a population can survive and sustain itself . to get at this number , you have to know the real breeding population of , say , grizzly bears in yellowstone national park . and then you figure out everything you can about a grizzly 's life history , how long they live , who gets to breed the most , how often they can have babies , that kind of thing . after all that information is collected , ecologists can run the numbers and figure out that , for the grizzlies in yellowstone , a population of , say hypothetically , 90 bears would have about a 95 % chance of surviving for 100 years . but if there were a population of 100 bears , the population would likely be able to survive for 200 years . something to note , ecology involves a lot of math . so if you 're interested in this , that 's just the way it is . so that 's the small population approach to conservation . another way of preserving biodiversity focuses on populations whose numbers are in decline , no matter how large the original population was . this is known as declining population conservation , and it involves answering a series of related questions that get at the root of what 's causing an organism 's numbers to nosedive . first , you have to determine whether the population 's actually declining . then you have to figure out how big the population historically was and what its requirements were . and finally , you have to get at what 's causing the decline and figure out how to address it . milltown dam actually gives us a good example of this process . in the winter of 1996 , authorities had to release some of the water behind the dam as an emergency measure because of a big ice floe in the river that was threatening to break the dam . but when they released the water , a bunch of toxic sediment went with it , which raised the copper concentrations downriver to almost 43 times what state standards allowed . as a result , it 's estimated that about half of the fish downstream died . half of the fish , dead . and researchers have been monitoring the decline in populations ever since . this information was really helpful in determining what to do with the dam because we knew what the fish population was like before and after the release of the sediment . it was decided that it would be best to get the dam out as soon as possible rather than risk another 1996 scenario . which brings me to the place where conservation biology and restoration ecology intersect . restoration ecology is kind of where the rubber meets the road in conservation biology . it comes up with possible solutions for ecological problems . now , short of a time machine , which i 'm working on , you ca n't really get a natural environment exactly the way that it used to be . but you can at least get rid of whatever is causing the problem , and help recreate some of the elements that the ecosystem needs to function properly . all of this involves a whole suite of strategies . for instance , what 's happening in milltown is an example of structural restoration , basically the removal and cleanup of whatever human impact was causing the problem , in this case , the dam and the toxic sediments behind it . and then the rebuilding of the historical natural structure , here the meanders of the river channel and the vegetation . another strategy is bioremediation , which recruits organisms temporarily to help remove toxins , like bacteria that eat wastes or plants that leach out metals from tainted soils . some kinds of fungi and bacteria are even being explored as ways to bioremediate oil spills . yet another , somewhat more invasive , restoration method is biological augmentation . rather than removing harmful substances , this involves adding organisms to the ecosystem to restore materials that are gone . plants that help fix nitrogen , like beans , acacia trees , and lupine , are often used to replenish nitrogen in soils that have been damaged by things like mining or overfarming . and ecologists sometimes add mycorrhizal fungi to help new plantings like native grass take hold . but of course , we 're just humans , and we 're not as smart as millions of years of evolution . sometimes we get things wrong . for example , when you bring an invasive species into a place to eradicate another invasive species . sometimes you just end up with two invasive species on your hands , which collapses the ecosystem even more rapidly . the introduction of cane toads to australia in the 1930s to control beetles is a particularly infamous example . not only are they everywhere now , but because they 're toxic , they 're poisoning native species like dingoes that try to eat them . nice . so you know what ? i have an idea . after spending the past couple of weeks talking about ecological problems , i 've come to the conclusion that it 's just easier to protect ecosystems rather than trying to fix them because we know a lot about what makes ecosystems tick . so if we spend more time trying to save them from us and our stuff , we 'll spend less time cleaning up after ourselves and running the risks of getting it wrong . because as we all know , the sad fact is uncooking bacon is impossible . but we can eat it . thank you for joining me on this quick three-month jaunt through the natural world . i hope it made you smarter , not just in terms of passing your exams , but also in terms of being a homo sapien that inhabits this planet more wisely .
|
sometimes you just end up with two invasive species on your hands , which collapses the ecosystem even more rapidly . the introduction of cane toads to australia in the 1930s to control beetles is a particularly infamous example . not only are they everywhere now , but because they 're toxic , they 're poisoning native species like dingoes that try to eat them . nice .
|
kill off all the cane toad eating dingoes ?
|
for the past 12 weeks , we 've been investigating our living planet together , learning how it works on many levels , how populations of organisms interact , how communities thrive and ecosystems change , and how humans are wrecking the nice , perfectly functioning systems earth has been using for hundreds of thousands of years . and now it 's graduation day . this here is like the commencement speech where i talk to you about the future and our role in it and how what we 're doing to the planet is totally awful , but we 're taking steps to undo some of the damage that we 've done . so what better way to wrap up our series on ecology than by taking a look at the growing fields of conservation biology and restoration ecology . these disciplines use all the kung fu moves that we 've learned about in the past 11 weeks and apply them to protecting ecosystems and cleaning up the messes that we 've already made . and one of the main things they teach us is that doing these things is difficult , like in the way that uncooking bacon is difficult . so let 's look at what we 're doing and try to uncook this unbelievably large pile of bacon we 've made . just outside of missoula , montana , where i live , we 've got a superfund site . not super-fun . superfund , a hazardous waste site that the government is in charge of cleaning up . the mess here was made more than 100 years ago , when there was a dam in the clark fork river behind me called the milltown dam . this part of montana has a long history of copper mining , and back in 1908 , there was a humongous flood that washed about 4.5 million cubic meters of mine tailings chock full of arsenic and toxic heavy metals into the clark fork river . and most of it washed into the reservoir created by the milltown dam . i mean , actually it was lucky that the dam was there -- it had only been completed six months before -- or the whole river system all the way to the pacific ocean would have been a toxic mess . as it happened , though , only about 160 kilometers of the river was all toxic , messed up . a lot of it recuperated over time . but all that nasty hazardous waste was still sitting behind milltown dam . and some of it leached into the groundwater that started polluting nearby residents ' wells . so scientists spent decades studying the extent of the damage caused by the waste and coming up with ways to fix it . and from 2006 to 2010 , engineers carefully removed all the toxic sediment as well as the dam itself . now this stretch of the clark fork river runs unimpeded for the first time in over a century , and the restored area where the dam used to be is being turned into a state park . efforts like this show us conservation biology and restoration ecology in action . conservation biology involves measuring the biodiversity of an ecosystem and determining how to protect it . in this case , it was used to size up the health of fish populations in the clark fork river , which were severely affected by the waste behind the dam , and the damn blocking their access to spawning grounds upstream , and figuring out how to protect them during the dam 's removal . restoration ecology , meanwhile , is the science of restoring broken ecosystems , like taking an interrupted , polluted river and turning it into what you see taking shape here . these do-gooder , fix-it-up sciences are practical rather than theoretical , by which i mean in order to fix something that 's broken , you 've got to have a good idea of what 's making it work to begin with . if something goes wrong with the expansion of the universe , we would n't be able to fix it because we have no idea at all what 's making all that happen . so in order to fix a failing ecosystem , you have to figure out what was holding it together in the first place . and the glue that holds every ecosystem together is biodiversity . but then , of course , biodiversity can mean many different things . so far , we 've generally used it to mean species diversity , or the variety of species in an ecosystem . but there are also other ways of talking about biodiversity that help conservation biologists and restoration ecologists figure out how to save species and repair ecosystems . in addition to diversity of species , ecologists look at genetic diversity within a species , as a whole and between populations . genetic diversity is important because it makes evolution possible by allowing a species to adapt to new situations like disease and climate change . and then another level of biodiversity has to do with ecosystem diversity , or the variety of different ecosystems within an area . a big , old forest , for example , can host several different kinds of ecosystems , like wetland , alpine , and aquatic ones . just like we talked about when we covered ecological succession , the more little pockets you 've got performing different functions , the more resilient the region will be as a whole . so , yeah . understanding all of this is really important to figuring out how to repair an ecosystem that is in shambles . but how do conservation biologists take the information about what makes an ecosystem tick and use it to save the place from going under ? well , there 's more than one way to approach this problem . one way is called small population conservation . this approach focuses on identifying species and populations that are really small , and tries to help boost their numbers and genetic diversity . low population and low genetic diversity are kind of a death knell for a species . they actually feed off each other , one problem making the other problem worse , ultimately causing a species to spiral into extinction . see , when a tiny little population suffers from inbreeding or genetic drift , that is , a shift in its overall genetic makeup , this leads to even less diversity , which in turn causes lower reproduction rates and higher mortality rates , which makes the population smaller still . this terrible little dynamic is known by the awesome term extinction vortex . the next step is to figure out how small a population is too small . ecologists do this by calculating what 's called the minimum viable population , which is the smallest size at which a population can survive and sustain itself . to get at this number , you have to know the real breeding population of , say , grizzly bears in yellowstone national park . and then you figure out everything you can about a grizzly 's life history , how long they live , who gets to breed the most , how often they can have babies , that kind of thing . after all that information is collected , ecologists can run the numbers and figure out that , for the grizzlies in yellowstone , a population of , say hypothetically , 90 bears would have about a 95 % chance of surviving for 100 years . but if there were a population of 100 bears , the population would likely be able to survive for 200 years . something to note , ecology involves a lot of math . so if you 're interested in this , that 's just the way it is . so that 's the small population approach to conservation . another way of preserving biodiversity focuses on populations whose numbers are in decline , no matter how large the original population was . this is known as declining population conservation , and it involves answering a series of related questions that get at the root of what 's causing an organism 's numbers to nosedive . first , you have to determine whether the population 's actually declining . then you have to figure out how big the population historically was and what its requirements were . and finally , you have to get at what 's causing the decline and figure out how to address it . milltown dam actually gives us a good example of this process . in the winter of 1996 , authorities had to release some of the water behind the dam as an emergency measure because of a big ice floe in the river that was threatening to break the dam . but when they released the water , a bunch of toxic sediment went with it , which raised the copper concentrations downriver to almost 43 times what state standards allowed . as a result , it 's estimated that about half of the fish downstream died . half of the fish , dead . and researchers have been monitoring the decline in populations ever since . this information was really helpful in determining what to do with the dam because we knew what the fish population was like before and after the release of the sediment . it was decided that it would be best to get the dam out as soon as possible rather than risk another 1996 scenario . which brings me to the place where conservation biology and restoration ecology intersect . restoration ecology is kind of where the rubber meets the road in conservation biology . it comes up with possible solutions for ecological problems . now , short of a time machine , which i 'm working on , you ca n't really get a natural environment exactly the way that it used to be . but you can at least get rid of whatever is causing the problem , and help recreate some of the elements that the ecosystem needs to function properly . all of this involves a whole suite of strategies . for instance , what 's happening in milltown is an example of structural restoration , basically the removal and cleanup of whatever human impact was causing the problem , in this case , the dam and the toxic sediments behind it . and then the rebuilding of the historical natural structure , here the meanders of the river channel and the vegetation . another strategy is bioremediation , which recruits organisms temporarily to help remove toxins , like bacteria that eat wastes or plants that leach out metals from tainted soils . some kinds of fungi and bacteria are even being explored as ways to bioremediate oil spills . yet another , somewhat more invasive , restoration method is biological augmentation . rather than removing harmful substances , this involves adding organisms to the ecosystem to restore materials that are gone . plants that help fix nitrogen , like beans , acacia trees , and lupine , are often used to replenish nitrogen in soils that have been damaged by things like mining or overfarming . and ecologists sometimes add mycorrhizal fungi to help new plantings like native grass take hold . but of course , we 're just humans , and we 're not as smart as millions of years of evolution . sometimes we get things wrong . for example , when you bring an invasive species into a place to eradicate another invasive species . sometimes you just end up with two invasive species on your hands , which collapses the ecosystem even more rapidly . the introduction of cane toads to australia in the 1930s to control beetles is a particularly infamous example . not only are they everywhere now , but because they 're toxic , they 're poisoning native species like dingoes that try to eat them . nice . so you know what ? i have an idea . after spending the past couple of weeks talking about ecological problems , i 've come to the conclusion that it 's just easier to protect ecosystems rather than trying to fix them because we know a lot about what makes ecosystems tick . so if we spend more time trying to save them from us and our stuff , we 'll spend less time cleaning up after ourselves and running the risks of getting it wrong . because as we all know , the sad fact is uncooking bacon is impossible . but we can eat it . thank you for joining me on this quick three-month jaunt through the natural world . i hope it made you smarter , not just in terms of passing your exams , but also in terms of being a homo sapien that inhabits this planet more wisely .
|
sometimes we get things wrong . for example , when you bring an invasive species into a place to eradicate another invasive species . sometimes you just end up with two invasive species on your hands , which collapses the ecosystem even more rapidly . the introduction of cane toads to australia in the 1930s to control beetles is a particularly infamous example .
|
are there any examples of good invasive species which have benefited an ecosystem ?
|
for the past 12 weeks , we 've been investigating our living planet together , learning how it works on many levels , how populations of organisms interact , how communities thrive and ecosystems change , and how humans are wrecking the nice , perfectly functioning systems earth has been using for hundreds of thousands of years . and now it 's graduation day . this here is like the commencement speech where i talk to you about the future and our role in it and how what we 're doing to the planet is totally awful , but we 're taking steps to undo some of the damage that we 've done . so what better way to wrap up our series on ecology than by taking a look at the growing fields of conservation biology and restoration ecology . these disciplines use all the kung fu moves that we 've learned about in the past 11 weeks and apply them to protecting ecosystems and cleaning up the messes that we 've already made . and one of the main things they teach us is that doing these things is difficult , like in the way that uncooking bacon is difficult . so let 's look at what we 're doing and try to uncook this unbelievably large pile of bacon we 've made . just outside of missoula , montana , where i live , we 've got a superfund site . not super-fun . superfund , a hazardous waste site that the government is in charge of cleaning up . the mess here was made more than 100 years ago , when there was a dam in the clark fork river behind me called the milltown dam . this part of montana has a long history of copper mining , and back in 1908 , there was a humongous flood that washed about 4.5 million cubic meters of mine tailings chock full of arsenic and toxic heavy metals into the clark fork river . and most of it washed into the reservoir created by the milltown dam . i mean , actually it was lucky that the dam was there -- it had only been completed six months before -- or the whole river system all the way to the pacific ocean would have been a toxic mess . as it happened , though , only about 160 kilometers of the river was all toxic , messed up . a lot of it recuperated over time . but all that nasty hazardous waste was still sitting behind milltown dam . and some of it leached into the groundwater that started polluting nearby residents ' wells . so scientists spent decades studying the extent of the damage caused by the waste and coming up with ways to fix it . and from 2006 to 2010 , engineers carefully removed all the toxic sediment as well as the dam itself . now this stretch of the clark fork river runs unimpeded for the first time in over a century , and the restored area where the dam used to be is being turned into a state park . efforts like this show us conservation biology and restoration ecology in action . conservation biology involves measuring the biodiversity of an ecosystem and determining how to protect it . in this case , it was used to size up the health of fish populations in the clark fork river , which were severely affected by the waste behind the dam , and the damn blocking their access to spawning grounds upstream , and figuring out how to protect them during the dam 's removal . restoration ecology , meanwhile , is the science of restoring broken ecosystems , like taking an interrupted , polluted river and turning it into what you see taking shape here . these do-gooder , fix-it-up sciences are practical rather than theoretical , by which i mean in order to fix something that 's broken , you 've got to have a good idea of what 's making it work to begin with . if something goes wrong with the expansion of the universe , we would n't be able to fix it because we have no idea at all what 's making all that happen . so in order to fix a failing ecosystem , you have to figure out what was holding it together in the first place . and the glue that holds every ecosystem together is biodiversity . but then , of course , biodiversity can mean many different things . so far , we 've generally used it to mean species diversity , or the variety of species in an ecosystem . but there are also other ways of talking about biodiversity that help conservation biologists and restoration ecologists figure out how to save species and repair ecosystems . in addition to diversity of species , ecologists look at genetic diversity within a species , as a whole and between populations . genetic diversity is important because it makes evolution possible by allowing a species to adapt to new situations like disease and climate change . and then another level of biodiversity has to do with ecosystem diversity , or the variety of different ecosystems within an area . a big , old forest , for example , can host several different kinds of ecosystems , like wetland , alpine , and aquatic ones . just like we talked about when we covered ecological succession , the more little pockets you 've got performing different functions , the more resilient the region will be as a whole . so , yeah . understanding all of this is really important to figuring out how to repair an ecosystem that is in shambles . but how do conservation biologists take the information about what makes an ecosystem tick and use it to save the place from going under ? well , there 's more than one way to approach this problem . one way is called small population conservation . this approach focuses on identifying species and populations that are really small , and tries to help boost their numbers and genetic diversity . low population and low genetic diversity are kind of a death knell for a species . they actually feed off each other , one problem making the other problem worse , ultimately causing a species to spiral into extinction . see , when a tiny little population suffers from inbreeding or genetic drift , that is , a shift in its overall genetic makeup , this leads to even less diversity , which in turn causes lower reproduction rates and higher mortality rates , which makes the population smaller still . this terrible little dynamic is known by the awesome term extinction vortex . the next step is to figure out how small a population is too small . ecologists do this by calculating what 's called the minimum viable population , which is the smallest size at which a population can survive and sustain itself . to get at this number , you have to know the real breeding population of , say , grizzly bears in yellowstone national park . and then you figure out everything you can about a grizzly 's life history , how long they live , who gets to breed the most , how often they can have babies , that kind of thing . after all that information is collected , ecologists can run the numbers and figure out that , for the grizzlies in yellowstone , a population of , say hypothetically , 90 bears would have about a 95 % chance of surviving for 100 years . but if there were a population of 100 bears , the population would likely be able to survive for 200 years . something to note , ecology involves a lot of math . so if you 're interested in this , that 's just the way it is . so that 's the small population approach to conservation . another way of preserving biodiversity focuses on populations whose numbers are in decline , no matter how large the original population was . this is known as declining population conservation , and it involves answering a series of related questions that get at the root of what 's causing an organism 's numbers to nosedive . first , you have to determine whether the population 's actually declining . then you have to figure out how big the population historically was and what its requirements were . and finally , you have to get at what 's causing the decline and figure out how to address it . milltown dam actually gives us a good example of this process . in the winter of 1996 , authorities had to release some of the water behind the dam as an emergency measure because of a big ice floe in the river that was threatening to break the dam . but when they released the water , a bunch of toxic sediment went with it , which raised the copper concentrations downriver to almost 43 times what state standards allowed . as a result , it 's estimated that about half of the fish downstream died . half of the fish , dead . and researchers have been monitoring the decline in populations ever since . this information was really helpful in determining what to do with the dam because we knew what the fish population was like before and after the release of the sediment . it was decided that it would be best to get the dam out as soon as possible rather than risk another 1996 scenario . which brings me to the place where conservation biology and restoration ecology intersect . restoration ecology is kind of where the rubber meets the road in conservation biology . it comes up with possible solutions for ecological problems . now , short of a time machine , which i 'm working on , you ca n't really get a natural environment exactly the way that it used to be . but you can at least get rid of whatever is causing the problem , and help recreate some of the elements that the ecosystem needs to function properly . all of this involves a whole suite of strategies . for instance , what 's happening in milltown is an example of structural restoration , basically the removal and cleanup of whatever human impact was causing the problem , in this case , the dam and the toxic sediments behind it . and then the rebuilding of the historical natural structure , here the meanders of the river channel and the vegetation . another strategy is bioremediation , which recruits organisms temporarily to help remove toxins , like bacteria that eat wastes or plants that leach out metals from tainted soils . some kinds of fungi and bacteria are even being explored as ways to bioremediate oil spills . yet another , somewhat more invasive , restoration method is biological augmentation . rather than removing harmful substances , this involves adding organisms to the ecosystem to restore materials that are gone . plants that help fix nitrogen , like beans , acacia trees , and lupine , are often used to replenish nitrogen in soils that have been damaged by things like mining or overfarming . and ecologists sometimes add mycorrhizal fungi to help new plantings like native grass take hold . but of course , we 're just humans , and we 're not as smart as millions of years of evolution . sometimes we get things wrong . for example , when you bring an invasive species into a place to eradicate another invasive species . sometimes you just end up with two invasive species on your hands , which collapses the ecosystem even more rapidly . the introduction of cane toads to australia in the 1930s to control beetles is a particularly infamous example . not only are they everywhere now , but because they 're toxic , they 're poisoning native species like dingoes that try to eat them . nice . so you know what ? i have an idea . after spending the past couple of weeks talking about ecological problems , i 've come to the conclusion that it 's just easier to protect ecosystems rather than trying to fix them because we know a lot about what makes ecosystems tick . so if we spend more time trying to save them from us and our stuff , we 'll spend less time cleaning up after ourselves and running the risks of getting it wrong . because as we all know , the sad fact is uncooking bacon is impossible . but we can eat it . thank you for joining me on this quick three-month jaunt through the natural world . i hope it made you smarter , not just in terms of passing your exams , but also in terms of being a homo sapien that inhabits this planet more wisely .
|
but if there were a population of 100 bears , the population would likely be able to survive for 200 years . something to note , ecology involves a lot of math . so if you 're interested in this , that 's just the way it is .
|
and , on an unrelated side note , is there a bacteria/archae/protist that is capable of turning co2 into oxygen and organic carbon ?
|
for the past 12 weeks , we 've been investigating our living planet together , learning how it works on many levels , how populations of organisms interact , how communities thrive and ecosystems change , and how humans are wrecking the nice , perfectly functioning systems earth has been using for hundreds of thousands of years . and now it 's graduation day . this here is like the commencement speech where i talk to you about the future and our role in it and how what we 're doing to the planet is totally awful , but we 're taking steps to undo some of the damage that we 've done . so what better way to wrap up our series on ecology than by taking a look at the growing fields of conservation biology and restoration ecology . these disciplines use all the kung fu moves that we 've learned about in the past 11 weeks and apply them to protecting ecosystems and cleaning up the messes that we 've already made . and one of the main things they teach us is that doing these things is difficult , like in the way that uncooking bacon is difficult . so let 's look at what we 're doing and try to uncook this unbelievably large pile of bacon we 've made . just outside of missoula , montana , where i live , we 've got a superfund site . not super-fun . superfund , a hazardous waste site that the government is in charge of cleaning up . the mess here was made more than 100 years ago , when there was a dam in the clark fork river behind me called the milltown dam . this part of montana has a long history of copper mining , and back in 1908 , there was a humongous flood that washed about 4.5 million cubic meters of mine tailings chock full of arsenic and toxic heavy metals into the clark fork river . and most of it washed into the reservoir created by the milltown dam . i mean , actually it was lucky that the dam was there -- it had only been completed six months before -- or the whole river system all the way to the pacific ocean would have been a toxic mess . as it happened , though , only about 160 kilometers of the river was all toxic , messed up . a lot of it recuperated over time . but all that nasty hazardous waste was still sitting behind milltown dam . and some of it leached into the groundwater that started polluting nearby residents ' wells . so scientists spent decades studying the extent of the damage caused by the waste and coming up with ways to fix it . and from 2006 to 2010 , engineers carefully removed all the toxic sediment as well as the dam itself . now this stretch of the clark fork river runs unimpeded for the first time in over a century , and the restored area where the dam used to be is being turned into a state park . efforts like this show us conservation biology and restoration ecology in action . conservation biology involves measuring the biodiversity of an ecosystem and determining how to protect it . in this case , it was used to size up the health of fish populations in the clark fork river , which were severely affected by the waste behind the dam , and the damn blocking their access to spawning grounds upstream , and figuring out how to protect them during the dam 's removal . restoration ecology , meanwhile , is the science of restoring broken ecosystems , like taking an interrupted , polluted river and turning it into what you see taking shape here . these do-gooder , fix-it-up sciences are practical rather than theoretical , by which i mean in order to fix something that 's broken , you 've got to have a good idea of what 's making it work to begin with . if something goes wrong with the expansion of the universe , we would n't be able to fix it because we have no idea at all what 's making all that happen . so in order to fix a failing ecosystem , you have to figure out what was holding it together in the first place . and the glue that holds every ecosystem together is biodiversity . but then , of course , biodiversity can mean many different things . so far , we 've generally used it to mean species diversity , or the variety of species in an ecosystem . but there are also other ways of talking about biodiversity that help conservation biologists and restoration ecologists figure out how to save species and repair ecosystems . in addition to diversity of species , ecologists look at genetic diversity within a species , as a whole and between populations . genetic diversity is important because it makes evolution possible by allowing a species to adapt to new situations like disease and climate change . and then another level of biodiversity has to do with ecosystem diversity , or the variety of different ecosystems within an area . a big , old forest , for example , can host several different kinds of ecosystems , like wetland , alpine , and aquatic ones . just like we talked about when we covered ecological succession , the more little pockets you 've got performing different functions , the more resilient the region will be as a whole . so , yeah . understanding all of this is really important to figuring out how to repair an ecosystem that is in shambles . but how do conservation biologists take the information about what makes an ecosystem tick and use it to save the place from going under ? well , there 's more than one way to approach this problem . one way is called small population conservation . this approach focuses on identifying species and populations that are really small , and tries to help boost their numbers and genetic diversity . low population and low genetic diversity are kind of a death knell for a species . they actually feed off each other , one problem making the other problem worse , ultimately causing a species to spiral into extinction . see , when a tiny little population suffers from inbreeding or genetic drift , that is , a shift in its overall genetic makeup , this leads to even less diversity , which in turn causes lower reproduction rates and higher mortality rates , which makes the population smaller still . this terrible little dynamic is known by the awesome term extinction vortex . the next step is to figure out how small a population is too small . ecologists do this by calculating what 's called the minimum viable population , which is the smallest size at which a population can survive and sustain itself . to get at this number , you have to know the real breeding population of , say , grizzly bears in yellowstone national park . and then you figure out everything you can about a grizzly 's life history , how long they live , who gets to breed the most , how often they can have babies , that kind of thing . after all that information is collected , ecologists can run the numbers and figure out that , for the grizzlies in yellowstone , a population of , say hypothetically , 90 bears would have about a 95 % chance of surviving for 100 years . but if there were a population of 100 bears , the population would likely be able to survive for 200 years . something to note , ecology involves a lot of math . so if you 're interested in this , that 's just the way it is . so that 's the small population approach to conservation . another way of preserving biodiversity focuses on populations whose numbers are in decline , no matter how large the original population was . this is known as declining population conservation , and it involves answering a series of related questions that get at the root of what 's causing an organism 's numbers to nosedive . first , you have to determine whether the population 's actually declining . then you have to figure out how big the population historically was and what its requirements were . and finally , you have to get at what 's causing the decline and figure out how to address it . milltown dam actually gives us a good example of this process . in the winter of 1996 , authorities had to release some of the water behind the dam as an emergency measure because of a big ice floe in the river that was threatening to break the dam . but when they released the water , a bunch of toxic sediment went with it , which raised the copper concentrations downriver to almost 43 times what state standards allowed . as a result , it 's estimated that about half of the fish downstream died . half of the fish , dead . and researchers have been monitoring the decline in populations ever since . this information was really helpful in determining what to do with the dam because we knew what the fish population was like before and after the release of the sediment . it was decided that it would be best to get the dam out as soon as possible rather than risk another 1996 scenario . which brings me to the place where conservation biology and restoration ecology intersect . restoration ecology is kind of where the rubber meets the road in conservation biology . it comes up with possible solutions for ecological problems . now , short of a time machine , which i 'm working on , you ca n't really get a natural environment exactly the way that it used to be . but you can at least get rid of whatever is causing the problem , and help recreate some of the elements that the ecosystem needs to function properly . all of this involves a whole suite of strategies . for instance , what 's happening in milltown is an example of structural restoration , basically the removal and cleanup of whatever human impact was causing the problem , in this case , the dam and the toxic sediments behind it . and then the rebuilding of the historical natural structure , here the meanders of the river channel and the vegetation . another strategy is bioremediation , which recruits organisms temporarily to help remove toxins , like bacteria that eat wastes or plants that leach out metals from tainted soils . some kinds of fungi and bacteria are even being explored as ways to bioremediate oil spills . yet another , somewhat more invasive , restoration method is biological augmentation . rather than removing harmful substances , this involves adding organisms to the ecosystem to restore materials that are gone . plants that help fix nitrogen , like beans , acacia trees , and lupine , are often used to replenish nitrogen in soils that have been damaged by things like mining or overfarming . and ecologists sometimes add mycorrhizal fungi to help new plantings like native grass take hold . but of course , we 're just humans , and we 're not as smart as millions of years of evolution . sometimes we get things wrong . for example , when you bring an invasive species into a place to eradicate another invasive species . sometimes you just end up with two invasive species on your hands , which collapses the ecosystem even more rapidly . the introduction of cane toads to australia in the 1930s to control beetles is a particularly infamous example . not only are they everywhere now , but because they 're toxic , they 're poisoning native species like dingoes that try to eat them . nice . so you know what ? i have an idea . after spending the past couple of weeks talking about ecological problems , i 've come to the conclusion that it 's just easier to protect ecosystems rather than trying to fix them because we know a lot about what makes ecosystems tick . so if we spend more time trying to save them from us and our stuff , we 'll spend less time cleaning up after ourselves and running the risks of getting it wrong . because as we all know , the sad fact is uncooking bacon is impossible . but we can eat it . thank you for joining me on this quick three-month jaunt through the natural world . i hope it made you smarter , not just in terms of passing your exams , but also in terms of being a homo sapien that inhabits this planet more wisely .
|
and finally , you have to get at what 's causing the decline and figure out how to address it . milltown dam actually gives us a good example of this process . in the winter of 1996 , authorities had to release some of the water behind the dam as an emergency measure because of a big ice floe in the river that was threatening to break the dam . but when they released the water , a bunch of toxic sediment went with it , which raised the copper concentrations downriver to almost 43 times what state standards allowed .
|
0 wouldnt the ice break the dam anyway so it looked to me either way the fish would die ?
|
for the past 12 weeks , we 've been investigating our living planet together , learning how it works on many levels , how populations of organisms interact , how communities thrive and ecosystems change , and how humans are wrecking the nice , perfectly functioning systems earth has been using for hundreds of thousands of years . and now it 's graduation day . this here is like the commencement speech where i talk to you about the future and our role in it and how what we 're doing to the planet is totally awful , but we 're taking steps to undo some of the damage that we 've done . so what better way to wrap up our series on ecology than by taking a look at the growing fields of conservation biology and restoration ecology . these disciplines use all the kung fu moves that we 've learned about in the past 11 weeks and apply them to protecting ecosystems and cleaning up the messes that we 've already made . and one of the main things they teach us is that doing these things is difficult , like in the way that uncooking bacon is difficult . so let 's look at what we 're doing and try to uncook this unbelievably large pile of bacon we 've made . just outside of missoula , montana , where i live , we 've got a superfund site . not super-fun . superfund , a hazardous waste site that the government is in charge of cleaning up . the mess here was made more than 100 years ago , when there was a dam in the clark fork river behind me called the milltown dam . this part of montana has a long history of copper mining , and back in 1908 , there was a humongous flood that washed about 4.5 million cubic meters of mine tailings chock full of arsenic and toxic heavy metals into the clark fork river . and most of it washed into the reservoir created by the milltown dam . i mean , actually it was lucky that the dam was there -- it had only been completed six months before -- or the whole river system all the way to the pacific ocean would have been a toxic mess . as it happened , though , only about 160 kilometers of the river was all toxic , messed up . a lot of it recuperated over time . but all that nasty hazardous waste was still sitting behind milltown dam . and some of it leached into the groundwater that started polluting nearby residents ' wells . so scientists spent decades studying the extent of the damage caused by the waste and coming up with ways to fix it . and from 2006 to 2010 , engineers carefully removed all the toxic sediment as well as the dam itself . now this stretch of the clark fork river runs unimpeded for the first time in over a century , and the restored area where the dam used to be is being turned into a state park . efforts like this show us conservation biology and restoration ecology in action . conservation biology involves measuring the biodiversity of an ecosystem and determining how to protect it . in this case , it was used to size up the health of fish populations in the clark fork river , which were severely affected by the waste behind the dam , and the damn blocking their access to spawning grounds upstream , and figuring out how to protect them during the dam 's removal . restoration ecology , meanwhile , is the science of restoring broken ecosystems , like taking an interrupted , polluted river and turning it into what you see taking shape here . these do-gooder , fix-it-up sciences are practical rather than theoretical , by which i mean in order to fix something that 's broken , you 've got to have a good idea of what 's making it work to begin with . if something goes wrong with the expansion of the universe , we would n't be able to fix it because we have no idea at all what 's making all that happen . so in order to fix a failing ecosystem , you have to figure out what was holding it together in the first place . and the glue that holds every ecosystem together is biodiversity . but then , of course , biodiversity can mean many different things . so far , we 've generally used it to mean species diversity , or the variety of species in an ecosystem . but there are also other ways of talking about biodiversity that help conservation biologists and restoration ecologists figure out how to save species and repair ecosystems . in addition to diversity of species , ecologists look at genetic diversity within a species , as a whole and between populations . genetic diversity is important because it makes evolution possible by allowing a species to adapt to new situations like disease and climate change . and then another level of biodiversity has to do with ecosystem diversity , or the variety of different ecosystems within an area . a big , old forest , for example , can host several different kinds of ecosystems , like wetland , alpine , and aquatic ones . just like we talked about when we covered ecological succession , the more little pockets you 've got performing different functions , the more resilient the region will be as a whole . so , yeah . understanding all of this is really important to figuring out how to repair an ecosystem that is in shambles . but how do conservation biologists take the information about what makes an ecosystem tick and use it to save the place from going under ? well , there 's more than one way to approach this problem . one way is called small population conservation . this approach focuses on identifying species and populations that are really small , and tries to help boost their numbers and genetic diversity . low population and low genetic diversity are kind of a death knell for a species . they actually feed off each other , one problem making the other problem worse , ultimately causing a species to spiral into extinction . see , when a tiny little population suffers from inbreeding or genetic drift , that is , a shift in its overall genetic makeup , this leads to even less diversity , which in turn causes lower reproduction rates and higher mortality rates , which makes the population smaller still . this terrible little dynamic is known by the awesome term extinction vortex . the next step is to figure out how small a population is too small . ecologists do this by calculating what 's called the minimum viable population , which is the smallest size at which a population can survive and sustain itself . to get at this number , you have to know the real breeding population of , say , grizzly bears in yellowstone national park . and then you figure out everything you can about a grizzly 's life history , how long they live , who gets to breed the most , how often they can have babies , that kind of thing . after all that information is collected , ecologists can run the numbers and figure out that , for the grizzlies in yellowstone , a population of , say hypothetically , 90 bears would have about a 95 % chance of surviving for 100 years . but if there were a population of 100 bears , the population would likely be able to survive for 200 years . something to note , ecology involves a lot of math . so if you 're interested in this , that 's just the way it is . so that 's the small population approach to conservation . another way of preserving biodiversity focuses on populations whose numbers are in decline , no matter how large the original population was . this is known as declining population conservation , and it involves answering a series of related questions that get at the root of what 's causing an organism 's numbers to nosedive . first , you have to determine whether the population 's actually declining . then you have to figure out how big the population historically was and what its requirements were . and finally , you have to get at what 's causing the decline and figure out how to address it . milltown dam actually gives us a good example of this process . in the winter of 1996 , authorities had to release some of the water behind the dam as an emergency measure because of a big ice floe in the river that was threatening to break the dam . but when they released the water , a bunch of toxic sediment went with it , which raised the copper concentrations downriver to almost 43 times what state standards allowed . as a result , it 's estimated that about half of the fish downstream died . half of the fish , dead . and researchers have been monitoring the decline in populations ever since . this information was really helpful in determining what to do with the dam because we knew what the fish population was like before and after the release of the sediment . it was decided that it would be best to get the dam out as soon as possible rather than risk another 1996 scenario . which brings me to the place where conservation biology and restoration ecology intersect . restoration ecology is kind of where the rubber meets the road in conservation biology . it comes up with possible solutions for ecological problems . now , short of a time machine , which i 'm working on , you ca n't really get a natural environment exactly the way that it used to be . but you can at least get rid of whatever is causing the problem , and help recreate some of the elements that the ecosystem needs to function properly . all of this involves a whole suite of strategies . for instance , what 's happening in milltown is an example of structural restoration , basically the removal and cleanup of whatever human impact was causing the problem , in this case , the dam and the toxic sediments behind it . and then the rebuilding of the historical natural structure , here the meanders of the river channel and the vegetation . another strategy is bioremediation , which recruits organisms temporarily to help remove toxins , like bacteria that eat wastes or plants that leach out metals from tainted soils . some kinds of fungi and bacteria are even being explored as ways to bioremediate oil spills . yet another , somewhat more invasive , restoration method is biological augmentation . rather than removing harmful substances , this involves adding organisms to the ecosystem to restore materials that are gone . plants that help fix nitrogen , like beans , acacia trees , and lupine , are often used to replenish nitrogen in soils that have been damaged by things like mining or overfarming . and ecologists sometimes add mycorrhizal fungi to help new plantings like native grass take hold . but of course , we 're just humans , and we 're not as smart as millions of years of evolution . sometimes we get things wrong . for example , when you bring an invasive species into a place to eradicate another invasive species . sometimes you just end up with two invasive species on your hands , which collapses the ecosystem even more rapidly . the introduction of cane toads to australia in the 1930s to control beetles is a particularly infamous example . not only are they everywhere now , but because they 're toxic , they 're poisoning native species like dingoes that try to eat them . nice . so you know what ? i have an idea . after spending the past couple of weeks talking about ecological problems , i 've come to the conclusion that it 's just easier to protect ecosystems rather than trying to fix them because we know a lot about what makes ecosystems tick . so if we spend more time trying to save them from us and our stuff , we 'll spend less time cleaning up after ourselves and running the risks of getting it wrong . because as we all know , the sad fact is uncooking bacon is impossible . but we can eat it . thank you for joining me on this quick three-month jaunt through the natural world . i hope it made you smarter , not just in terms of passing your exams , but also in terms of being a homo sapien that inhabits this planet more wisely .
|
as it happened , though , only about 160 kilometers of the river was all toxic , messed up . a lot of it recuperated over time . but all that nasty hazardous waste was still sitting behind milltown dam .
|
why did the toads that they talked about at the time of why did it poison every thing in its path ?
|
( lively piano music ) : we 're on the 4th floor of the museum of modern art in new york , and we 're looking at robert rauschenberg 's , `` bed . '' this is a combine , not quite a sculpture , not quite a painting , from 1955 . : so , combine means a combination of painting and sculpture ? : well , johns and rauschenberg were actually thinking about their art as between art and life , and what is that narrow space between the two ? : instead of thinking about it between painting and sculpture between these two things that symbolize fine art in the grand tradition , inserting life into that conversation . : life and wit . what we 're looking at is , in fact , the stuff of a real bed . we 're looking at a real pillow . we 're looking at a real pillowcase , and a handmade quilted blanket , sheets , but if you look closely , you 're also seeing pencil and paint . of course , all of this has been taken out of the horizontal where you could lie down on this , and put up on the wall . : i 'm reminded of pollock , of pollock painting on the floor , and then those pieces of canvas being picked up and put on the walls of a museum or a gallery . the other way i 'm reminded of pollock is in all the drips that we 're seeing here . : this is a reference that rauschenberg wanted you to come to . : the pollocks are just 5 years old , the great drip paintings . : that 's exactly right . this artist wanted you to be thinking about pollock . this is really a confrontation with pollock , with abstract expressionism broadly . that was the dominant contemporary art of this moment in 1955 . pollock would die the following year . : when i think about abstract expressionism , i think about the personal subjective experience of the artist on the canvas . i guess it makes sense to me that this is a bed , a place of our unconscious , of our dreams . : i think it 's also tongue-in-cheek . this notion that the abstract expressionist canvas was somehow the manifestation of the internal state of the artist . rauschenberg is saying , `` you really believe that ? `` well let me give you the actual arena of the dream . `` i 'm going to give you my bed . '' : so , you think he 's making fun in a way ? : absolutely . art historians sometimes talked about the kind of oedipal relationship between rauschenberg or younger artists , and the abstract expressionists that he was friends with at this time . : that makes this a kind of in-joke . : 1955 , in the work of people like johns and rauschenberg , is the moment when art moves from being modernist in its sincerity to a kind of post-modern attitude that is responsive and that is self-aware , a kind of hyper self-awareness . : we could understand that as a switch between modernism to post-modernism . : or sincerity to irony . : it is true that when i think about abstract expressionism , there is this attempt by each of those artists , newman , pollock , rothko , motherwell , the great artists of the abstract expressionist movement , each one of them has a very distinctive , individual style . you ca n't say that there 's an abstract expressionist style because it 's completely dependent on the individual . there is that idea that the painting is this manifestation of their personality , their psyche . : what happens here , is we have an artist who is self-consciously imitating that idea of the authentic . if you look closely , the drip had become , by 1955 , almost a kind of emblem of the authentic experience of the authentic moment . here , that is being replicated . there 's a kind of irony that 's built into it . i think of stepping back from buying that notion that art can be this true internal thing . : by virtue of copying what is supposed to be someone else 's individual style , there is a kind of irony , a kind of self-consciousness there , a kind of adopting for another purpose . : but then , all of this is [ laid over ] the found objects or objects from rauschenberg 's bed . there 's something incredibly personal , but also absurdist here . that 's why johnson and rauschenberg are sometimes referred to as neo-dadist , because they picked up the mantle , the flag of people like duchamp , who are interested in irony , in playfulness , in a reprising of ideas , and reconstructing of a vocabulary of meaning . : well , it is true that duchamp took on the tradition of western art and all its seriousness and high-mindedness . i can see that here with the rauschenberg in that commenting on the sincerity and seriousness of abstract expressionism . ( lively piano music )
|
this is a combine , not quite a sculpture , not quite a painting , from 1955 . : so , combine means a combination of painting and sculpture ? : well , johns and rauschenberg were actually thinking about their art as between art and life , and what is that narrow space between the two ?
|
so a combine is always something that 's more of a painting and less of a sculpture , as is the case here , or could it be a work that more readily resembles a sculpture , but also has elements of painting ?
|
( lively piano music ) : we 're on the 4th floor of the museum of modern art in new york , and we 're looking at robert rauschenberg 's , `` bed . '' this is a combine , not quite a sculpture , not quite a painting , from 1955 . : so , combine means a combination of painting and sculpture ? : well , johns and rauschenberg were actually thinking about their art as between art and life , and what is that narrow space between the two ? : instead of thinking about it between painting and sculpture between these two things that symbolize fine art in the grand tradition , inserting life into that conversation . : life and wit . what we 're looking at is , in fact , the stuff of a real bed . we 're looking at a real pillow . we 're looking at a real pillowcase , and a handmade quilted blanket , sheets , but if you look closely , you 're also seeing pencil and paint . of course , all of this has been taken out of the horizontal where you could lie down on this , and put up on the wall . : i 'm reminded of pollock , of pollock painting on the floor , and then those pieces of canvas being picked up and put on the walls of a museum or a gallery . the other way i 'm reminded of pollock is in all the drips that we 're seeing here . : this is a reference that rauschenberg wanted you to come to . : the pollocks are just 5 years old , the great drip paintings . : that 's exactly right . this artist wanted you to be thinking about pollock . this is really a confrontation with pollock , with abstract expressionism broadly . that was the dominant contemporary art of this moment in 1955 . pollock would die the following year . : when i think about abstract expressionism , i think about the personal subjective experience of the artist on the canvas . i guess it makes sense to me that this is a bed , a place of our unconscious , of our dreams . : i think it 's also tongue-in-cheek . this notion that the abstract expressionist canvas was somehow the manifestation of the internal state of the artist . rauschenberg is saying , `` you really believe that ? `` well let me give you the actual arena of the dream . `` i 'm going to give you my bed . '' : so , you think he 's making fun in a way ? : absolutely . art historians sometimes talked about the kind of oedipal relationship between rauschenberg or younger artists , and the abstract expressionists that he was friends with at this time . : that makes this a kind of in-joke . : 1955 , in the work of people like johns and rauschenberg , is the moment when art moves from being modernist in its sincerity to a kind of post-modern attitude that is responsive and that is self-aware , a kind of hyper self-awareness . : we could understand that as a switch between modernism to post-modernism . : or sincerity to irony . : it is true that when i think about abstract expressionism , there is this attempt by each of those artists , newman , pollock , rothko , motherwell , the great artists of the abstract expressionist movement , each one of them has a very distinctive , individual style . you ca n't say that there 's an abstract expressionist style because it 's completely dependent on the individual . there is that idea that the painting is this manifestation of their personality , their psyche . : what happens here , is we have an artist who is self-consciously imitating that idea of the authentic . if you look closely , the drip had become , by 1955 , almost a kind of emblem of the authentic experience of the authentic moment . here , that is being replicated . there 's a kind of irony that 's built into it . i think of stepping back from buying that notion that art can be this true internal thing . : by virtue of copying what is supposed to be someone else 's individual style , there is a kind of irony , a kind of self-consciousness there , a kind of adopting for another purpose . : but then , all of this is [ laid over ] the found objects or objects from rauschenberg 's bed . there 's something incredibly personal , but also absurdist here . that 's why johnson and rauschenberg are sometimes referred to as neo-dadist , because they picked up the mantle , the flag of people like duchamp , who are interested in irony , in playfulness , in a reprising of ideas , and reconstructing of a vocabulary of meaning . : well , it is true that duchamp took on the tradition of western art and all its seriousness and high-mindedness . i can see that here with the rauschenberg in that commenting on the sincerity and seriousness of abstract expressionism . ( lively piano music )
|
: so , combine means a combination of painting and sculpture ? : well , johns and rauschenberg were actually thinking about their art as between art and life , and what is that narrow space between the two ? : instead of thinking about it between painting and sculpture between these two things that symbolize fine art in the grand tradition , inserting life into that conversation .
|
what challenges to conserving of art are presented when the art is made from things like pillows , quilts , sheets and housepaint ?
|
( lively piano music ) : we 're on the 4th floor of the museum of modern art in new york , and we 're looking at robert rauschenberg 's , `` bed . '' this is a combine , not quite a sculpture , not quite a painting , from 1955 . : so , combine means a combination of painting and sculpture ? : well , johns and rauschenberg were actually thinking about their art as between art and life , and what is that narrow space between the two ? : instead of thinking about it between painting and sculpture between these two things that symbolize fine art in the grand tradition , inserting life into that conversation . : life and wit . what we 're looking at is , in fact , the stuff of a real bed . we 're looking at a real pillow . we 're looking at a real pillowcase , and a handmade quilted blanket , sheets , but if you look closely , you 're also seeing pencil and paint . of course , all of this has been taken out of the horizontal where you could lie down on this , and put up on the wall . : i 'm reminded of pollock , of pollock painting on the floor , and then those pieces of canvas being picked up and put on the walls of a museum or a gallery . the other way i 'm reminded of pollock is in all the drips that we 're seeing here . : this is a reference that rauschenberg wanted you to come to . : the pollocks are just 5 years old , the great drip paintings . : that 's exactly right . this artist wanted you to be thinking about pollock . this is really a confrontation with pollock , with abstract expressionism broadly . that was the dominant contemporary art of this moment in 1955 . pollock would die the following year . : when i think about abstract expressionism , i think about the personal subjective experience of the artist on the canvas . i guess it makes sense to me that this is a bed , a place of our unconscious , of our dreams . : i think it 's also tongue-in-cheek . this notion that the abstract expressionist canvas was somehow the manifestation of the internal state of the artist . rauschenberg is saying , `` you really believe that ? `` well let me give you the actual arena of the dream . `` i 'm going to give you my bed . '' : so , you think he 's making fun in a way ? : absolutely . art historians sometimes talked about the kind of oedipal relationship between rauschenberg or younger artists , and the abstract expressionists that he was friends with at this time . : that makes this a kind of in-joke . : 1955 , in the work of people like johns and rauschenberg , is the moment when art moves from being modernist in its sincerity to a kind of post-modern attitude that is responsive and that is self-aware , a kind of hyper self-awareness . : we could understand that as a switch between modernism to post-modernism . : or sincerity to irony . : it is true that when i think about abstract expressionism , there is this attempt by each of those artists , newman , pollock , rothko , motherwell , the great artists of the abstract expressionist movement , each one of them has a very distinctive , individual style . you ca n't say that there 's an abstract expressionist style because it 's completely dependent on the individual . there is that idea that the painting is this manifestation of their personality , their psyche . : what happens here , is we have an artist who is self-consciously imitating that idea of the authentic . if you look closely , the drip had become , by 1955 , almost a kind of emblem of the authentic experience of the authentic moment . here , that is being replicated . there 's a kind of irony that 's built into it . i think of stepping back from buying that notion that art can be this true internal thing . : by virtue of copying what is supposed to be someone else 's individual style , there is a kind of irony , a kind of self-consciousness there , a kind of adopting for another purpose . : but then , all of this is [ laid over ] the found objects or objects from rauschenberg 's bed . there 's something incredibly personal , but also absurdist here . that 's why johnson and rauschenberg are sometimes referred to as neo-dadist , because they picked up the mantle , the flag of people like duchamp , who are interested in irony , in playfulness , in a reprising of ideas , and reconstructing of a vocabulary of meaning . : well , it is true that duchamp took on the tradition of western art and all its seriousness and high-mindedness . i can see that here with the rauschenberg in that commenting on the sincerity and seriousness of abstract expressionism . ( lively piano music )
|
what we 're looking at is , in fact , the stuff of a real bed . we 're looking at a real pillow . we 're looking at a real pillowcase , and a handmade quilted blanket , sheets , but if you look closely , you 're also seeing pencil and paint .
|
to use artifacts from the real world in their work ?
|
we 've already seen scenarios where we start with a differential equation and then we generate a slope field that describes the solutions to the differential equation and then we use that to visualize those solutions . what i want to do in this video is do an exercise that takes us the other way , start with a slope field and figure out which differential equation is the slope field describing the solutions for . and so i encourage you to look at each of these options and think about which of these differential equations is being described by this slope field . i encourage you to pause the video right now and try it on your own . so i 'm assuming you have had a go at it . so let 's work through each of them . and the way i 'm going to do it is i 'm just going to find some points that seem to be easy to do arithmetic with , and we 'll see if the slope described by the differential equation at that point is consistent with the slope depicted in the slope field . and , i do n't know , just for simplicity , maybe i 'll do x equals one and y equals one for all of these . so , when x equals one and y is equal to one . so , this first differential equation right over here , if x is one and y is one , then dy/dx would be negative one over one or negative one . dy/dx would be negative one . now , is that depicted here ? when x is equal to one and y is equal to one , our slope is n't negative one . our slope here looks positive . so we can rule this one out . now , let 's try the next one . so , if x is equal to one and y is equal to one , well then dy/dx would be equal to one minus one or zero . and , once again , i just picked x equals one and y equals one for convenience . i could have picked any other . i could have picked negative five and negative seven . this just makes the arithmetic a little easier . once again , when you look at that point that we 've already looked at , our slope is clearly not zero . we have a positive slope here , so we can rule that out . once again , for this magenta differential equation , if x and y are both equal to one , then one minus one is once again going to be equal to zero . and we 've already seen this slope is not zero here , so rule that one out . and now here we have x plus y , so when x is one and y is one , our derivate of y with respect to x is going to be one plus one , which is equal to two . now , this looks interesting . it looks like this slope right over here could be two . this looks like one . this looks like two . i would want to validate some other points , but this looks like a really , really good candidate . and you can also see what is happening here . when dy/dx is equal to x plus y , you would expect that as x increases for a given y your slope would increase and as y increases for a given x your slope increases . and we see that . if we were to just hold y constant at one but increase x along this line , we see that the slope is increasing . it is getting steeper . and if we were to keep x constant and increase y across this line , we see that the slope increases . and , in general , we see that the slope increases as we go to the top right . and we see that it decreases as we go to the bottom left and both x and y become much , much more negative . so , i 'm feeling pretty good about this , especially if we can knock this one out here , if we can knock that one out . so , dy/dx is equal to x over y . well , then when x equals one and y equals one , dy/dx would be equal to one , and this slope looks larger than one . it looks like two , but since we are really just eyeballing it , let 's see if we can find something where this more clearly falls apart . so , let 's look at the situation when they both equal negative one . so , x equals negative one and y is equal to negative one . well , in that case , dy/dx should still be equal to one because you have negative one over one . do we see that over here ? so , when x is equal to negative one , y is equal to negative one . our derivative here looks negative . it looks like negative two , which is consistent with this yellow differential equation . the slope here is definitely not a positive one , so we could rule this one out as well . and so we should feel pretty confident that this is the differential equation being described . and now that we 've done it , we can actually think about well , okay , what are the solutions for this differential equation going to look like . well , it depends where they start or what points they contain . if you have a solution that contains that point , it looks like it might do something like this . if you had a solution that contained this point , it might do something like that . and , of course , it keeps going . it looks like it would asymptote towards y is equal to negative x , this downward sloping . this essentially is the line y is equal to negative x . actually , no that is not the line y equals negative x . this is the line y is equal to negative x minus one , so that 's this line right over here . and it looks like if the solution contained , say , this point right over here , that would actually be a solution to the differential equation y is equal to negative x minus one and you can verify that . if y is equal to negative x minus one , then the x and negative x cancel out and you are just left with dy/dx is equal to negative one , which is exactly what is being described by this slope field . anyway , hopefully you found that interesting .
|
so , i 'm feeling pretty good about this , especially if we can knock this one out here , if we can knock that one out . so , dy/dx is equal to x over y . well , then when x equals one and y equals one , dy/dx would be equal to one , and this slope looks larger than one .
|
dy/dx = x+y -y dy = x dx 1/2 y^2 = 1/2x^2 + c1 then use an initial value to solve for the constant , which i did for 1 , -3 and ended up with y^2 = -x^2 + 10 am i even remotely on the right track here ?
|
we 've already seen scenarios where we start with a differential equation and then we generate a slope field that describes the solutions to the differential equation and then we use that to visualize those solutions . what i want to do in this video is do an exercise that takes us the other way , start with a slope field and figure out which differential equation is the slope field describing the solutions for . and so i encourage you to look at each of these options and think about which of these differential equations is being described by this slope field . i encourage you to pause the video right now and try it on your own . so i 'm assuming you have had a go at it . so let 's work through each of them . and the way i 'm going to do it is i 'm just going to find some points that seem to be easy to do arithmetic with , and we 'll see if the slope described by the differential equation at that point is consistent with the slope depicted in the slope field . and , i do n't know , just for simplicity , maybe i 'll do x equals one and y equals one for all of these . so , when x equals one and y is equal to one . so , this first differential equation right over here , if x is one and y is one , then dy/dx would be negative one over one or negative one . dy/dx would be negative one . now , is that depicted here ? when x is equal to one and y is equal to one , our slope is n't negative one . our slope here looks positive . so we can rule this one out . now , let 's try the next one . so , if x is equal to one and y is equal to one , well then dy/dx would be equal to one minus one or zero . and , once again , i just picked x equals one and y equals one for convenience . i could have picked any other . i could have picked negative five and negative seven . this just makes the arithmetic a little easier . once again , when you look at that point that we 've already looked at , our slope is clearly not zero . we have a positive slope here , so we can rule that out . once again , for this magenta differential equation , if x and y are both equal to one , then one minus one is once again going to be equal to zero . and we 've already seen this slope is not zero here , so rule that one out . and now here we have x plus y , so when x is one and y is one , our derivate of y with respect to x is going to be one plus one , which is equal to two . now , this looks interesting . it looks like this slope right over here could be two . this looks like one . this looks like two . i would want to validate some other points , but this looks like a really , really good candidate . and you can also see what is happening here . when dy/dx is equal to x plus y , you would expect that as x increases for a given y your slope would increase and as y increases for a given x your slope increases . and we see that . if we were to just hold y constant at one but increase x along this line , we see that the slope is increasing . it is getting steeper . and if we were to keep x constant and increase y across this line , we see that the slope increases . and , in general , we see that the slope increases as we go to the top right . and we see that it decreases as we go to the bottom left and both x and y become much , much more negative . so , i 'm feeling pretty good about this , especially if we can knock this one out here , if we can knock that one out . so , dy/dx is equal to x over y . well , then when x equals one and y equals one , dy/dx would be equal to one , and this slope looks larger than one . it looks like two , but since we are really just eyeballing it , let 's see if we can find something where this more clearly falls apart . so , let 's look at the situation when they both equal negative one . so , x equals negative one and y is equal to negative one . well , in that case , dy/dx should still be equal to one because you have negative one over one . do we see that over here ? so , when x is equal to negative one , y is equal to negative one . our derivative here looks negative . it looks like negative two , which is consistent with this yellow differential equation . the slope here is definitely not a positive one , so we could rule this one out as well . and so we should feel pretty confident that this is the differential equation being described . and now that we 've done it , we can actually think about well , okay , what are the solutions for this differential equation going to look like . well , it depends where they start or what points they contain . if you have a solution that contains that point , it looks like it might do something like this . if you had a solution that contained this point , it might do something like that . and , of course , it keeps going . it looks like it would asymptote towards y is equal to negative x , this downward sloping . this essentially is the line y is equal to negative x . actually , no that is not the line y equals negative x . this is the line y is equal to negative x minus one , so that 's this line right over here . and it looks like if the solution contained , say , this point right over here , that would actually be a solution to the differential equation y is equal to negative x minus one and you can verify that . if y is equal to negative x minus one , then the x and negative x cancel out and you are just left with dy/dx is equal to negative one , which is exactly what is being described by this slope field . anyway , hopefully you found that interesting .
|
our derivative here looks negative . it looks like negative two , which is consistent with this yellow differential equation . the slope here is definitely not a positive one , so we could rule this one out as well .
|
how do you solve the differential equation if we ca n't separate the variables ?
|
we 've already seen scenarios where we start with a differential equation and then we generate a slope field that describes the solutions to the differential equation and then we use that to visualize those solutions . what i want to do in this video is do an exercise that takes us the other way , start with a slope field and figure out which differential equation is the slope field describing the solutions for . and so i encourage you to look at each of these options and think about which of these differential equations is being described by this slope field . i encourage you to pause the video right now and try it on your own . so i 'm assuming you have had a go at it . so let 's work through each of them . and the way i 'm going to do it is i 'm just going to find some points that seem to be easy to do arithmetic with , and we 'll see if the slope described by the differential equation at that point is consistent with the slope depicted in the slope field . and , i do n't know , just for simplicity , maybe i 'll do x equals one and y equals one for all of these . so , when x equals one and y is equal to one . so , this first differential equation right over here , if x is one and y is one , then dy/dx would be negative one over one or negative one . dy/dx would be negative one . now , is that depicted here ? when x is equal to one and y is equal to one , our slope is n't negative one . our slope here looks positive . so we can rule this one out . now , let 's try the next one . so , if x is equal to one and y is equal to one , well then dy/dx would be equal to one minus one or zero . and , once again , i just picked x equals one and y equals one for convenience . i could have picked any other . i could have picked negative five and negative seven . this just makes the arithmetic a little easier . once again , when you look at that point that we 've already looked at , our slope is clearly not zero . we have a positive slope here , so we can rule that out . once again , for this magenta differential equation , if x and y are both equal to one , then one minus one is once again going to be equal to zero . and we 've already seen this slope is not zero here , so rule that one out . and now here we have x plus y , so when x is one and y is one , our derivate of y with respect to x is going to be one plus one , which is equal to two . now , this looks interesting . it looks like this slope right over here could be two . this looks like one . this looks like two . i would want to validate some other points , but this looks like a really , really good candidate . and you can also see what is happening here . when dy/dx is equal to x plus y , you would expect that as x increases for a given y your slope would increase and as y increases for a given x your slope increases . and we see that . if we were to just hold y constant at one but increase x along this line , we see that the slope is increasing . it is getting steeper . and if we were to keep x constant and increase y across this line , we see that the slope increases . and , in general , we see that the slope increases as we go to the top right . and we see that it decreases as we go to the bottom left and both x and y become much , much more negative . so , i 'm feeling pretty good about this , especially if we can knock this one out here , if we can knock that one out . so , dy/dx is equal to x over y . well , then when x equals one and y equals one , dy/dx would be equal to one , and this slope looks larger than one . it looks like two , but since we are really just eyeballing it , let 's see if we can find something where this more clearly falls apart . so , let 's look at the situation when they both equal negative one . so , x equals negative one and y is equal to negative one . well , in that case , dy/dx should still be equal to one because you have negative one over one . do we see that over here ? so , when x is equal to negative one , y is equal to negative one . our derivative here looks negative . it looks like negative two , which is consistent with this yellow differential equation . the slope here is definitely not a positive one , so we could rule this one out as well . and so we should feel pretty confident that this is the differential equation being described . and now that we 've done it , we can actually think about well , okay , what are the solutions for this differential equation going to look like . well , it depends where they start or what points they contain . if you have a solution that contains that point , it looks like it might do something like this . if you had a solution that contained this point , it might do something like that . and , of course , it keeps going . it looks like it would asymptote towards y is equal to negative x , this downward sloping . this essentially is the line y is equal to negative x . actually , no that is not the line y equals negative x . this is the line y is equal to negative x minus one , so that 's this line right over here . and it looks like if the solution contained , say , this point right over here , that would actually be a solution to the differential equation y is equal to negative x minus one and you can verify that . if y is equal to negative x minus one , then the x and negative x cancel out and you are just left with dy/dx is equal to negative one , which is exactly what is being described by this slope field . anyway , hopefully you found that interesting .
|
and it looks like if the solution contained , say , this point right over here , that would actually be a solution to the differential equation y is equal to negative x minus one and you can verify that . if y is equal to negative x minus one , then the x and negative x cancel out and you are just left with dy/dx is equal to negative one , which is exactly what is being described by this slope field . anyway , hopefully you found that interesting .
|
could n't you have just observed that the slop field vectors are level at ( 0,0 ) , ( 1 , -1 ) , ( 2 , -2 ) , which means y ' = 0 at those points thus y ' = x + y ?
|
we 've already seen scenarios where we start with a differential equation and then we generate a slope field that describes the solutions to the differential equation and then we use that to visualize those solutions . what i want to do in this video is do an exercise that takes us the other way , start with a slope field and figure out which differential equation is the slope field describing the solutions for . and so i encourage you to look at each of these options and think about which of these differential equations is being described by this slope field . i encourage you to pause the video right now and try it on your own . so i 'm assuming you have had a go at it . so let 's work through each of them . and the way i 'm going to do it is i 'm just going to find some points that seem to be easy to do arithmetic with , and we 'll see if the slope described by the differential equation at that point is consistent with the slope depicted in the slope field . and , i do n't know , just for simplicity , maybe i 'll do x equals one and y equals one for all of these . so , when x equals one and y is equal to one . so , this first differential equation right over here , if x is one and y is one , then dy/dx would be negative one over one or negative one . dy/dx would be negative one . now , is that depicted here ? when x is equal to one and y is equal to one , our slope is n't negative one . our slope here looks positive . so we can rule this one out . now , let 's try the next one . so , if x is equal to one and y is equal to one , well then dy/dx would be equal to one minus one or zero . and , once again , i just picked x equals one and y equals one for convenience . i could have picked any other . i could have picked negative five and negative seven . this just makes the arithmetic a little easier . once again , when you look at that point that we 've already looked at , our slope is clearly not zero . we have a positive slope here , so we can rule that out . once again , for this magenta differential equation , if x and y are both equal to one , then one minus one is once again going to be equal to zero . and we 've already seen this slope is not zero here , so rule that one out . and now here we have x plus y , so when x is one and y is one , our derivate of y with respect to x is going to be one plus one , which is equal to two . now , this looks interesting . it looks like this slope right over here could be two . this looks like one . this looks like two . i would want to validate some other points , but this looks like a really , really good candidate . and you can also see what is happening here . when dy/dx is equal to x plus y , you would expect that as x increases for a given y your slope would increase and as y increases for a given x your slope increases . and we see that . if we were to just hold y constant at one but increase x along this line , we see that the slope is increasing . it is getting steeper . and if we were to keep x constant and increase y across this line , we see that the slope increases . and , in general , we see that the slope increases as we go to the top right . and we see that it decreases as we go to the bottom left and both x and y become much , much more negative . so , i 'm feeling pretty good about this , especially if we can knock this one out here , if we can knock that one out . so , dy/dx is equal to x over y . well , then when x equals one and y equals one , dy/dx would be equal to one , and this slope looks larger than one . it looks like two , but since we are really just eyeballing it , let 's see if we can find something where this more clearly falls apart . so , let 's look at the situation when they both equal negative one . so , x equals negative one and y is equal to negative one . well , in that case , dy/dx should still be equal to one because you have negative one over one . do we see that over here ? so , when x is equal to negative one , y is equal to negative one . our derivative here looks negative . it looks like negative two , which is consistent with this yellow differential equation . the slope here is definitely not a positive one , so we could rule this one out as well . and so we should feel pretty confident that this is the differential equation being described . and now that we 've done it , we can actually think about well , okay , what are the solutions for this differential equation going to look like . well , it depends where they start or what points they contain . if you have a solution that contains that point , it looks like it might do something like this . if you had a solution that contained this point , it might do something like that . and , of course , it keeps going . it looks like it would asymptote towards y is equal to negative x , this downward sloping . this essentially is the line y is equal to negative x . actually , no that is not the line y equals negative x . this is the line y is equal to negative x minus one , so that 's this line right over here . and it looks like if the solution contained , say , this point right over here , that would actually be a solution to the differential equation y is equal to negative x minus one and you can verify that . if y is equal to negative x minus one , then the x and negative x cancel out and you are just left with dy/dx is equal to negative one , which is exactly what is being described by this slope field . anyway , hopefully you found that interesting .
|
and now that we 've done it , we can actually think about well , okay , what are the solutions for this differential equation going to look like . well , it depends where they start or what points they contain . if you have a solution that contains that point , it looks like it might do something like this .
|
what does sal mean when he said the solution depends on the points it contains ?
|
we 've already seen scenarios where we start with a differential equation and then we generate a slope field that describes the solutions to the differential equation and then we use that to visualize those solutions . what i want to do in this video is do an exercise that takes us the other way , start with a slope field and figure out which differential equation is the slope field describing the solutions for . and so i encourage you to look at each of these options and think about which of these differential equations is being described by this slope field . i encourage you to pause the video right now and try it on your own . so i 'm assuming you have had a go at it . so let 's work through each of them . and the way i 'm going to do it is i 'm just going to find some points that seem to be easy to do arithmetic with , and we 'll see if the slope described by the differential equation at that point is consistent with the slope depicted in the slope field . and , i do n't know , just for simplicity , maybe i 'll do x equals one and y equals one for all of these . so , when x equals one and y is equal to one . so , this first differential equation right over here , if x is one and y is one , then dy/dx would be negative one over one or negative one . dy/dx would be negative one . now , is that depicted here ? when x is equal to one and y is equal to one , our slope is n't negative one . our slope here looks positive . so we can rule this one out . now , let 's try the next one . so , if x is equal to one and y is equal to one , well then dy/dx would be equal to one minus one or zero . and , once again , i just picked x equals one and y equals one for convenience . i could have picked any other . i could have picked negative five and negative seven . this just makes the arithmetic a little easier . once again , when you look at that point that we 've already looked at , our slope is clearly not zero . we have a positive slope here , so we can rule that out . once again , for this magenta differential equation , if x and y are both equal to one , then one minus one is once again going to be equal to zero . and we 've already seen this slope is not zero here , so rule that one out . and now here we have x plus y , so when x is one and y is one , our derivate of y with respect to x is going to be one plus one , which is equal to two . now , this looks interesting . it looks like this slope right over here could be two . this looks like one . this looks like two . i would want to validate some other points , but this looks like a really , really good candidate . and you can also see what is happening here . when dy/dx is equal to x plus y , you would expect that as x increases for a given y your slope would increase and as y increases for a given x your slope increases . and we see that . if we were to just hold y constant at one but increase x along this line , we see that the slope is increasing . it is getting steeper . and if we were to keep x constant and increase y across this line , we see that the slope increases . and , in general , we see that the slope increases as we go to the top right . and we see that it decreases as we go to the bottom left and both x and y become much , much more negative . so , i 'm feeling pretty good about this , especially if we can knock this one out here , if we can knock that one out . so , dy/dx is equal to x over y . well , then when x equals one and y equals one , dy/dx would be equal to one , and this slope looks larger than one . it looks like two , but since we are really just eyeballing it , let 's see if we can find something where this more clearly falls apart . so , let 's look at the situation when they both equal negative one . so , x equals negative one and y is equal to negative one . well , in that case , dy/dx should still be equal to one because you have negative one over one . do we see that over here ? so , when x is equal to negative one , y is equal to negative one . our derivative here looks negative . it looks like negative two , which is consistent with this yellow differential equation . the slope here is definitely not a positive one , so we could rule this one out as well . and so we should feel pretty confident that this is the differential equation being described . and now that we 've done it , we can actually think about well , okay , what are the solutions for this differential equation going to look like . well , it depends where they start or what points they contain . if you have a solution that contains that point , it looks like it might do something like this . if you had a solution that contained this point , it might do something like that . and , of course , it keeps going . it looks like it would asymptote towards y is equal to negative x , this downward sloping . this essentially is the line y is equal to negative x . actually , no that is not the line y equals negative x . this is the line y is equal to negative x minus one , so that 's this line right over here . and it looks like if the solution contained , say , this point right over here , that would actually be a solution to the differential equation y is equal to negative x minus one and you can verify that . if y is equal to negative x minus one , then the x and negative x cancel out and you are just left with dy/dx is equal to negative one , which is exactly what is being described by this slope field . anyway , hopefully you found that interesting .
|
if you have a solution that contains that point , it looks like it might do something like this . if you had a solution that contained this point , it might do something like that . and , of course , it keeps going .
|
the shape of the graph is depended on the starting point and anything else ?
|
we 've already seen scenarios where we start with a differential equation and then we generate a slope field that describes the solutions to the differential equation and then we use that to visualize those solutions . what i want to do in this video is do an exercise that takes us the other way , start with a slope field and figure out which differential equation is the slope field describing the solutions for . and so i encourage you to look at each of these options and think about which of these differential equations is being described by this slope field . i encourage you to pause the video right now and try it on your own . so i 'm assuming you have had a go at it . so let 's work through each of them . and the way i 'm going to do it is i 'm just going to find some points that seem to be easy to do arithmetic with , and we 'll see if the slope described by the differential equation at that point is consistent with the slope depicted in the slope field . and , i do n't know , just for simplicity , maybe i 'll do x equals one and y equals one for all of these . so , when x equals one and y is equal to one . so , this first differential equation right over here , if x is one and y is one , then dy/dx would be negative one over one or negative one . dy/dx would be negative one . now , is that depicted here ? when x is equal to one and y is equal to one , our slope is n't negative one . our slope here looks positive . so we can rule this one out . now , let 's try the next one . so , if x is equal to one and y is equal to one , well then dy/dx would be equal to one minus one or zero . and , once again , i just picked x equals one and y equals one for convenience . i could have picked any other . i could have picked negative five and negative seven . this just makes the arithmetic a little easier . once again , when you look at that point that we 've already looked at , our slope is clearly not zero . we have a positive slope here , so we can rule that out . once again , for this magenta differential equation , if x and y are both equal to one , then one minus one is once again going to be equal to zero . and we 've already seen this slope is not zero here , so rule that one out . and now here we have x plus y , so when x is one and y is one , our derivate of y with respect to x is going to be one plus one , which is equal to two . now , this looks interesting . it looks like this slope right over here could be two . this looks like one . this looks like two . i would want to validate some other points , but this looks like a really , really good candidate . and you can also see what is happening here . when dy/dx is equal to x plus y , you would expect that as x increases for a given y your slope would increase and as y increases for a given x your slope increases . and we see that . if we were to just hold y constant at one but increase x along this line , we see that the slope is increasing . it is getting steeper . and if we were to keep x constant and increase y across this line , we see that the slope increases . and , in general , we see that the slope increases as we go to the top right . and we see that it decreases as we go to the bottom left and both x and y become much , much more negative . so , i 'm feeling pretty good about this , especially if we can knock this one out here , if we can knock that one out . so , dy/dx is equal to x over y . well , then when x equals one and y equals one , dy/dx would be equal to one , and this slope looks larger than one . it looks like two , but since we are really just eyeballing it , let 's see if we can find something where this more clearly falls apart . so , let 's look at the situation when they both equal negative one . so , x equals negative one and y is equal to negative one . well , in that case , dy/dx should still be equal to one because you have negative one over one . do we see that over here ? so , when x is equal to negative one , y is equal to negative one . our derivative here looks negative . it looks like negative two , which is consistent with this yellow differential equation . the slope here is definitely not a positive one , so we could rule this one out as well . and so we should feel pretty confident that this is the differential equation being described . and now that we 've done it , we can actually think about well , okay , what are the solutions for this differential equation going to look like . well , it depends where they start or what points they contain . if you have a solution that contains that point , it looks like it might do something like this . if you had a solution that contained this point , it might do something like that . and , of course , it keeps going . it looks like it would asymptote towards y is equal to negative x , this downward sloping . this essentially is the line y is equal to negative x . actually , no that is not the line y equals negative x . this is the line y is equal to negative x minus one , so that 's this line right over here . and it looks like if the solution contained , say , this point right over here , that would actually be a solution to the differential equation y is equal to negative x minus one and you can verify that . if y is equal to negative x minus one , then the x and negative x cancel out and you are just left with dy/dx is equal to negative one , which is exactly what is being described by this slope field . anyway , hopefully you found that interesting .
|
and you can also see what is happening here . when dy/dx is equal to x plus y , you would expect that as x increases for a given y your slope would increase and as y increases for a given x your slope increases . and we see that .
|
a man and his dog are runninng on a straight beach.at a given point in time the dog is 12m from his owner who strats running in a direction perpendicular to the beach with a certain constant speed.the dog runs twice as fast and always towards his owner.where do the man and and his dog meet ?
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.