text
stringlengths
2
2.33k
source
stringclasses
826 values
ductus arteriosus : shunt in the pulmonary trunk that diverts oxygenated blood back to the aorta
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
ductus venosus : shunt that causes oxygenated blood to bypass the fetal liver on its way to the inferior vena cava
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
ectoderm : primary germ layer that develops into the central and peripheral nervous systems, sensory organs, epidermis, hair, and nails
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
ectopic pregnancy : implantation of an embryo outside of the uterus
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
embryo : developing human during weeks 3–8
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
embryonic folding : process by which an embryo develops from a flat disc of cells to a three-dimensional shape resembling a cylinder
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
endoderm : primary germ layer that goes on to form the gastrointestinal tract, liver, pancreas, and lungs
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
epiblast : upper layer of cells of the embryonic disc that forms from the inner cell mass; gives rise to all three germ layers
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
episiotomy : incision made in the posterior vaginal wall and perineum that facilitates vaginal birth
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
expulsion : second stage of childbirth, during which the mother bears down with contractions; this stage ends in birth
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
fertilization : unification of genetic material from male and female haploid gametes
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
fertilization membrane : impenetrable barrier that coats a nascent zygote; part of the slow block to polyspermy
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
fetus : developing human during the time from the end of the embryonic period (week 9) to birth
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
foramen ovale : shunt that directly connects the right and left atria and helps divert oxygenated blood from the fetal pulmonary circuit
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
foremilk : watery, translucent breast milk that is secreted first during a feeding and is rich in lactose and protein; quenches the infant’s thirst
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
gastrulation : process of cell migration and differentiation into three primary germ layers following cleavage and implantation
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
genotype : complete genetic makeup of an individual
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
gestation : in human development, the period required for embryonic and fetal development in utero; pregnancy
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
heterozygous : having two different alleles for a given gene
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
hindmilk : opaque, creamy breast milk delivered toward the end of a feeding; rich in fat; satisfies the infant’s appetite
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
homozygous : having two identical alleles for a given gene
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
human chorionic gonadotropin (hCG) : hormone that directs the corpus luteum to survive, enlarge, and continue producing progesterone and estrogen to suppress menses and secure an environment suitable for the developing embryo
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
hypoblast : lower layer of cells of the embryonic disc that extend into the blastocoel to form the yolk sac
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
implantation : process by which a blastocyst embeds itself in the uterine endometrium
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
incomplete dominance : pattern of inheritance in which a heterozygous genotype expresses a phenotype intermediate between dominant and recessive phenotypes
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
inner cell mass : cluster of cells within the blastocyst that is fated to become the embryo
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
involution : postpartum shrinkage of the uterus back to its pre-pregnancy volume
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
karyotype : systematic arrangement of images of chromosomes into homologous pairs
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
lactation : process by which milk is synthesized and secreted from the mammary glands of the postpartum female breast in response to sucking at the nipple
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
lanugo : silk-like hairs that coat the fetus; shed later in fetal development
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
let-down reflex : release of milk from the alveoli triggered by infant suckling
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
lightening : descent of the fetus lower into the pelvis in late pregnancy; also called “dropping”
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
lochia : postpartum vaginal discharge that begins as blood and ends as a whitish discharge; the end of lochia signals that the site of placental attachment has healed
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
meconium : fetal wastes consisting of ingested amniotic fluid, cellular debris, mucus, and bile
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
mesoderm : primary germ layer that becomes the skeleton, muscles, connective tissue, heart, blood vessels, and kidneys
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
morula : tightly packed sphere of blastomeres that has reached the uterus but has not yet implanted itself
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
mutation : change in the nucleotide sequence of DNA
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
neural fold : elevated edge of the neural groove
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
neural plate : thickened layer of neuroepithelium that runs longitudinally along the dorsal surface of an embryo and gives rise to nervous system tissue
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
neural tube : precursor to structures of the central nervous system, formed by the invagination and separation of neuroepithelium
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
neurulation : embryonic process that establishes the central nervous system
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
nonshivering thermogenesis : process of breaking down brown adipose tissue to produce heat in the absence of a shivering response
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
notochord : rod-shaped, mesoderm-derived structure that provides support for growing fetus
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
organogenesis : development of the rudimentary structures of all of an embryo’s organs from the germ layers
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
parturition : childbirth
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
phenotype : physical or biochemical manifestation of the genotype; expression of the alleles
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
placenta : organ that forms during pregnancy to nourish the developing fetus; also regulates waste and gas exchange between mother and fetus
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
placenta previa : low placement of fetus within uterus causes placenta to partially or completely cover the opening of the cervix as it grows
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
placentation : formation of the placenta; complete by weeks 14–16 of pregnancy
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
polyspermy : penetration of an oocyte by more than one sperm
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
primitive streak : indentation along the dorsal surface of the epiblast through which cells migrate to form the endoderm and mesoderm during gastrulation
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
prolactin : pituitary hormone that establishes and maintains the supply of breast milk; also important for the mobilization of maternal micronutrients for breast milk
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
Punnett square : grid used to display all possible combinations of alleles transmitted by parents to offspring and predict the mathematical probability of offspring inheriting a given genotype
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
quickening : fetal movements that are strong enough to be felt by the mother
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
recessive : describes a trait that is only expressed in homozygous form and is masked in heterozygous form
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
recessive lethal : inheritance pattern in which individuals with two copies of a lethal allele do not survive in utero or have a shortened life span
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
sex chromosomes : pair of chromosomes involved in sex determination; in males, the XY chromosomes; in females, the XX chromosomes
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
shunt : circulatory shortcut that diverts the flow of blood from one region to another
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
somite : one of the paired, repeating blocks of tissue located on either side of the notochord in the early embryo
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
syncytiotrophoblast : superficial cells of the trophoblast that fuse to form a multinucleated body that digests endometrial cells to firmly secure the blastocyst to the uterine wall
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
trait : variation of an expressed characteristic
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
trimester : division of the duration of a pregnancy into three 3-month terms
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
trophoblast : fluid-filled shell of squamous cells destined to become the chorionic villi, placenta, and associated fetal membranes
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
true labor : regular contractions that immediately precede childbirth; they do not abate with hydration or rest, and they become more frequent and powerful with time
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
umbilical cord : connection between the developing conceptus and the placenta; carries deoxygenated blood and wastes from the fetus and returns nutrients and oxygen from the mother
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
vernix caseosa : waxy, cheese-like substance that protects the delicate fetal skin until birth
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
X-linked : pattern of inheritance in which an allele is carried on the X chromosome of the 23rd pair
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
X-linked dominant : pattern of dominant inheritance that corresponds to a gene on the X chromosome of the 23rd pair
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
X-linked recessive : pattern of recessive inheritance that corresponds to a gene on the X chromosome of the 23rd pair
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
yolk sac : membrane associated with primitive circulation to the developing embryo; source of the first blood cells and germ cells and contributes to the umbilical cord structure
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
zona pellucida : thick, gel-like glycoprotein membrane that coats the oocyte and must be penetrated by sperm before fertilization can occur
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
zygote : fertilized egg; a diploid cell resulting from the fertilization of haploid gametes from the male and female lines
https://openstax.org/books/anatomy-and-physiology-2e/pages/28-key-terms
accelerate : to change velocity; to speed up, slow down, or change direction.
https://openstax.org/books/astronomy-2e/pages/2-key-terms
apparent magnitude : a measure of how bright a star looks in the sky; the larger the number, the dimmer the star appears to us
https://openstax.org/books/astronomy-2e/pages/2-key-terms
astrology : the pseudoscience that deals with the supposed influences on human destiny of the configurations and locations in the sky of the Sun, Moon, and planets
https://openstax.org/books/astronomy-2e/pages/2-key-terms
celestial equator : a great circle on the celestial sphere 90° from the celestial poles; where the celestial sphere intersects the plane of Earth’s equator
https://openstax.org/books/astronomy-2e/pages/2-key-terms
celestial poles : points about which the celestial sphere appears to rotate; intersections of the celestial sphere with Earth’s polar axis
https://openstax.org/books/astronomy-2e/pages/2-key-terms
celestial sphere : the apparent sphere of the sky; a sphere of large radius centered on the observer; directions of objects in the sky can be denoted by their position on the celestial sphere
https://openstax.org/books/astronomy-2e/pages/2-key-terms
circumpolar zone : those portions of the celestial sphere near the celestial poles that are either always above or always below the horizon
https://openstax.org/books/astronomy-2e/pages/2-key-terms
cosmology : the study of the organization and evolution of the universe
https://openstax.org/books/astronomy-2e/pages/2-key-terms
ecliptic : the apparent annual path of the Sun on the celestial sphere
https://openstax.org/books/astronomy-2e/pages/2-key-terms
epicycle : the circular orbit of a body in the Ptolemaic system, the center of which revolves about another circle (the deferent)
https://openstax.org/books/astronomy-2e/pages/2-key-terms
geocentric : centered on Earth
https://openstax.org/books/astronomy-2e/pages/2-key-terms
heliocentric : centered on the Sun
https://openstax.org/books/astronomy-2e/pages/2-key-terms
horizon (astronomical) : a great circle on the celestial sphere 90° from the zenith; more popularly, the circle around us where the dome of the sky meets Earth
https://openstax.org/books/astronomy-2e/pages/2-key-terms
horoscope : a chart used by astrologers that shows the positions along the zodiac and in the sky of the Sun, Moon, and planets at some given instant and as seen from a particular place on Earth—usually corresponding to the time and place of a person’s birth
https://openstax.org/books/astronomy-2e/pages/2-key-terms
parallax : the apparent displacement of a nearby star that results from the motion of Earth around the Sun
https://openstax.org/books/astronomy-2e/pages/2-key-terms
planet : today, any of the larger objects revolving about the Sun or any similar objects that orbit other stars; in ancient times, any object that moved regularly among the fixed stars
https://openstax.org/books/astronomy-2e/pages/2-key-terms
precession (of Earth) : the slow, conical motion of Earth’s axis of rotation caused principally by the gravitational pull of the Moon and Sun on Earth’s equatorial bulge
https://openstax.org/books/astronomy-2e/pages/2-key-terms
retrograde motion : the apparent westward motion of a planet on the celestial sphere or with respect to the stars
https://openstax.org/books/astronomy-2e/pages/2-key-terms
year : the period of revolution of Earth around the Sun
https://openstax.org/books/astronomy-2e/pages/2-key-terms
zenith : the point on the celestial sphere opposite the direction of gravity; point directly above the observer
https://openstax.org/books/astronomy-2e/pages/2-key-terms
zodiac : a belt around the sky about 18° wide centered on the ecliptic
https://openstax.org/books/astronomy-2e/pages/2-key-terms
The direct evidence of our senses supports a geocentric perspective, with the celestial sphere pivoting on the celestial poles and rotating about a stationary Earth. We see only half of this sphere at one time, limited by the horizon; the point directly overhead is our zenith. The Sun’s annual path on the celestial s...
https://openstax.org/books/astronomy-2e/pages/2-summary
Ancient Greeks such as Aristotle recognized that Earth and the Moon are spheres, and understood the phases of the Moon, but because of their inability to detect stellar parallax, they rejected the idea that Earth moves. Eratosthenes measured the size of Earth with surprising precision. Hipparchus carried out many astro...
https://openstax.org/books/astronomy-2e/pages/2-summary
The ancient religion of astrology, with its main contribution to civilization a heightened interest in the heavens, began in Babylonia. It reached its peak in the Greco-Roman world, especially as recorded in theTetrabiblosof Ptolemy. Natal astrology is based on the assumption that the positions of the planets at the ti...
https://openstax.org/books/astronomy-2e/pages/2-summary
Nicolaus Copernicus introduced the heliocentric cosmology to Renaissance Europe in his bookDe Revolutionibus. Although he retained the Aristotelian idea of uniform circular motion, Copernicus suggested that Earth is a planet and that the planets all circle about the Sun, dethroning Earth from its position at the center...
https://openstax.org/books/astronomy-2e/pages/2-summary
angular momentum : the measure of the motion of a rotating object in terms of its speed and how widely the object’s mass is distributed around its axis
https://openstax.org/books/astronomy-2e/pages/3-key-terms
aphelion : the point in its orbit where a planet (or other orbiting object) is farthest from the Sun
https://openstax.org/books/astronomy-2e/pages/3-key-terms
apogee : the point in its orbit where an Earth satellite is farthest from Earth
https://openstax.org/books/astronomy-2e/pages/3-key-terms