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Therefore, conduction of heat from the body to the air is self-limited unless the heated air moves away from the skin, so new, unheated air is continually brought in contact with the skin, a phenomenon called air convection. Convective Heat Loss Results From Air Movement. Heat from the skin is first *conducte...	{ "Header 1": "Body Temperature Regulation and Fever", "token_count": 1995, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Acclimatization of the Sweating Mechanism to Heat—The Role of Aldosterone. Although a normal, unacclimatized person seldom produces more than about 1 liter of sweat per hour, when this person is exposed to hot weather for 1 to 6 weeks, he or she begins to sweat more profusely, often increasing maximum sweat produ...	{ "Header 1": "Body Temperature Regulation and Fever", "token_count": 2034, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Skin vasoconstriction throughout the body. This vasoconstriction is caused by stimulation of the posterior hypothalamic sympathetic centers. - 2. Piloerection. Piloerection means hairs "standing on end." Sympathetic stimulation causes the arrector ![](_page_859_Figure_2.jpeg) Figure 74-7. Effect of hypothal...	{ "Header 1": "Body Temperature Regulation and Fever", "token_count": 1336, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
In the example of Figure 74-7, it is clear that at a critical body core temperature of about 37.1°C (98.8°F), drastic changes occur in the rates of both heat loss and heat production. At temperatures above this level, the rate of heat loss is greater than that of heat production, so the body temperature falls and a...	{ "Header 1": "Body Temperature Regulation and Fever", "Header 2": "\"SET POINT\" FOR TEMPERATURE CONTROL", "token_count": 919, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Aside from the subconscious mechanisms for body temperature control, the body has another temperature-control mechanism that is even more potent—behavioral control of temperature. Whenever the internal body temperature becomes too high, signals from the temperature-controlling areas in the brain give the person a psy...	{ "Header 1": "Body Temperature Regulation and Fever", "Header 2": "BEHAVIORAL CONTROL OF BODY TEMPERATURE", "token_count": 517, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### FEVER Fever, which means a body temperature above the usual range of normal, can be caused by abnormalities in the brain or by toxic substances that affect the temperature-regulating centers. Some causes of fever (and also of subnormal body temperatures) are presented in Figure 74-10. They include bacter...	{ "Header 1": "Body Temperature Regulation and Fever", "Header 2": "ABNORMALITIES OF BODY TEMPERATURE REGULATION", "token_count": 2040, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### Exposure of the Body to Extreme Cold Unless treated immediately, a person exposed to ice water for 20 to 30 minutes ordinarily dies because of heart standstill or heart fibrillation. By that time, the internal body temperature will have fallen to about 77°F. If warmed rapidly by the application of external...	{ "Header 1": "Body Temperature Regulation and Fever", "Header 2": "ABNORMALITIES OF BODY TEMPERATURE REGULATION", "token_count": 1352, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### COORDINATION OF BODY FUNCTIONS BY CHEMICAL MESSENGERS The multiple activities of the cells, tissues, and organs of the body are coordinated by the interplay of several types of chemical messenger systems: - 1. Neurotransmitters are released by axon terminals of neurons into the synaptic junctions and act loc...	{ "Header 1": "Introduction to Endocrinology", "token_count": 1812, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Hormone secretion occurs when the amines are split from Table 75-1 Endocrine Glands, Hormones, and Their Functions and Structure \| Gland/Tissue \| Hormones \| Major Functions ...	{ "Header 1": "Introduction to Endocrinology", "token_count": 2019, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Concentrations of Hormones in the Circulating Blood and Hormonal Secretion Rates. The concentrations of hormones required to control most metabolic and endocrine functions are incredibly small. Their concentrations in the blood range from as little as 1 picogram (which is one millionth of one millionth of a gram)...	{ "Header 1": "Introduction to Endocrinology", "token_count": 2024, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The Number and Sensitivity of Hormone Receptors Are Regulated. The number of receptors in a target cell usually does not remain constant from day to day or even from minute to minute. Receptor proteins are often inactivated or destroyed during the course of their function, and at other times they are reactivated ...	{ "Header 1": "Introduction to Endocrinology", "token_count": 2029, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
JAK2 phosphorylation also activates several other enzyme systems that mediate some of the more rapid effects of leptin. Y, Specific tyrosine phosphorylation sites. special transmembrane receptor, which then becomes the activated enzyme adenylyl cyclase at the end that protrudes to the interior of the cell. This cyc...	{ "Header 1": "Introduction to Endocrinology", "token_count": 2040, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### Calcium-Calmodulin Second Messenger System Another second messenger system operates in response to entry of calcium into the cells. Calcium entry may be initiated by (1) changes in membrane potential that open calcium channels or (2) a hormone interacting with membrane receptors that open calcium channels....	{ "Header 1": "Introduction to Endocrinology", "token_count": 2042, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The amount of the product is measured using optical methods and is proportional to the amount of hormone in the well if there are excess antibodies in the well. #### Bibliography Aguiar-Oliveira MH, Bartke A: Growth hormone deficiency: health and longevity. Endocr Rev 40:575, 2019. Baker ME: Steroid receptors and...	{ "Header 1": "Introduction to Endocrinology", "token_count": 906, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### PITUITARY GLAND AND ITS RELATION TO THE HYPOTHALAMUS #### ANTERIOR AND POSTERIOR LOBES OF THE PITUITARY GLAND The pituitary gland ([Figure 76-1](#page-878-0)), also called the hypophysis, is a small gland—about 1 centimeter in diameter and 0.5 to 1 gram in weight—that lies in the sella turcica, a...	{ "Header 1": "Pituitary Hormones and Their Control by the Hypothalamus", "token_count": 1351, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Almost all pituitary secretion is controlled by hormonal or nervous signals from the hypothalamus. Indeed, when the pituitary gland is removed from its normal position beneath the hypothalamus and transplanted to some other part of the body, its secretion rates of the different hormones (except for prolactin) fall to v...	{ "Header 1": "Pituitary Hormones and Their Control by the Hypothalamus", "Header 2": "HYPOTHALAMUS CONTROLS PITUITARY SECRETION", "token_count": 2034, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Specific Areas in the Hypothalamus Control Secretion of Specific Hypothalamic Releasing and Inhibitory Hormones. All or most of the hypothalamic hormones are secreted at nerve endings in the median eminence before being transported to the anterior pituitary gland. Electrical stimulation of this region excites the...	{ "Header 1": "Pituitary Hormones and Their Control by the Hypothalamus", "Header 2": "HYPOTHALAMUS CONTROLS PITUITARY SECRETION", "token_count": 897, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Over more prolonged periods (24–48 hours), GH also stimulates transcription of DNA in the nucleus, causing formation of increased quantities of RNA. This promotes more ![](_page_882_Figure_12.jpeg) Figure 76-6. Effects of growth hormone and insulin-like growth factor -1 (IGF-1) on growth and metabolism. Growth ...	{ "Header 1": "Pituitary Hormones and Their Control by the Hypothalamus", "Header 2": "Increased Nuclear Transcription of DNA to Form RNA.", "token_count": 2043, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
One possible explanation for this finding is that GH can cause formation of enough IGF-1 in the local tissue to cause local growth. However, GH also has IGF-independent effects that stimulate growth in some tissues such as chondrocytes of cartilage. **Short Duration of Action of Growth Hormone but Prolonged Action of...	{ "Header 1": "Pituitary Hormones and Their Control by the Hypothalamus", "Header 2": "Increased Nuclear Transcription of DNA to Form RNA.", "token_count": 1999, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Thus, the picture is that of a lethargic person (from lack of thyroid hormones) who is gaining weight (because of lack of fat mobilization by growth, adrenocorticotropic, adrenocortical, and thyroid hormones) and has lost all sexual functions. Except for the abnormal sexual functions, the patient can usually be treated...	{ "Header 1": "Pituitary Hormones and Their Control by the Hypothalamus", "Header 2": "Increased Nuclear Transcription of DNA to Form RNA.", "token_count": 2045, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Their amino acid sequences are the following: Vasopressin: Cys-Tyr-Phe-Gln-Asn-Cys-Pro-Arg-GlyNH2 Oxytocin: Cys-Tyr-Ile-Gln-Asn-Cys-Pro-Leu-GlyNH<sup>2</sup> Note that these two hormones are almost identical except that in vasopressin, phenylalanine and arginine replace isoleucine and leucine of the oxytoci...	{ "Header 1": "Pituitary Hormones and Their Control by the Hypothalamus", "Header 2": "Increased Nuclear Transcription of DNA to Form RNA.", "token_count": 1993, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Physiol Rev 98:2225, 2018. - Freeman ME, Kanyicska B, Lerant A, Nagy G: Prolactin: structure, function, and regulation of secretion. Physiol Rev 80:1523, 2000. - Gimpl G, Fahrenholz F: The oxytocin receptor system: structure, function, and regulation. Physiol Rev 81:629, 2001. - Hannon AM, Thompson CJ, Sherlock M: Diab...	{ "Header 1": "Pituitary Hormones and Their Control by the Hypothalamus", "Header 2": "Increased Nuclear Transcription of DNA to Form RNA.", "token_count": 560, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The thyroid gland, located immediately below the larynx on each side of and anterior to the trachea, is one of the largest of the endocrine glands, normally weighing 15 to 20 grams in adults. The thyroid secretes two major metabolic hormones, thyroxine and triiodothyronine, commonly called T4 and T3, respective...	{ "Header 1": "Thyroid Metabolic Hormones", "token_count": 1237, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Formation and Secretion of Thyroglobulin by the Thyroid Cells. The thyroid cells are typical protein-secreting glandular cells, as shown in Figure 77-2. The endoplasmic reticulum and Golgi apparatus synthesize and secrete into the follicles a large glycoprotein molecule called thyroglobulin, with a molecular weight o...	{ "Header 1": "Thyroid Metabolic Hormones", "Header 2": "THYROGLOBULIN AND FORMATION OF THYROXINE AND TRIIODOTHYRONINE", "token_count": 2041, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Half the thyroxine in the blood is released to the tissue cells about every 6 days, whereas half the triiodothyronine—because of its lower affinity—is released to the cells in about 1 day. Upon entering the tissue cells, both thyroxine and triiodothyronine again bind with intracellular proteins, with the thyroxine bi...	{ "Header 1": "Thyroid Metabolic Hormones", "Header 2": "THYROGLOBULIN AND FORMATION OF THYROXINE AND TRIIODOTHYRONINE", "token_count": 2035, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Effect on Plasma and Liver Fats. Increased thyroid hormone decreases the concentrations of cholesterol, phospholipids, and triglycerides in the plasma, even though it increases the free fatty acids. Conversely, decreased thyroid secretion greatly increases the plasma concentrations of cholesterol, phosp...	{ "Header 1": "Thyroid Metabolic Hormones", "Header 2": "THYROGLOBULIN AND FORMATION OF THYROXINE AND TRIIODOTHYRONINE", "token_count": 2035, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Increased activity of the iodide pump, which increases the rate of "iodide trapping" in the glandular cells, sometimes increasing the ratio of intracellular to extracellular iodide concentration in the glandular substance to as much as eight times normal - 3. Increased iodination of tyrosine to form the thyroid hor...	{ "Header 1": "Thyroid Metabolic Hormones", "Header 2": "THYROGLOBULIN AND FORMATION OF THYROXINE AND TRIIODOTHYRONINE", "token_count": 1159, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Increased thyroid hormone in the body fluids decreases TSH secretion by the anterior pituitary. When the rate of thyroid hormone secretion rises to about 1.75 times normal, the rate of TSH secretion falls essentially to zero. Almost all this feedback depressant effect occurs even when the anterior pituitary has been se...	{ "Header 1": "FEEDBACK EFFECT OF THYROID HORMONE TO DECREASE ANTERIOR PITUITARY SECRETION OF TSH", "token_count": 1999, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
In the usual type of thyrotoxicosis, anterior pituitary secretion of TSH is so completely sup- - pressed by the large amounts of circulating thyroxine and triiodothyronine that there is almost no plasma TSH. - 3. The concentration of TSI is measured by immunoassay. This concentration is usually high in thyrotoxicosis...	{ "Header 1": "FEEDBACK EFFECT OF THYROID HORMONE TO DECREASE ANTERIOR PITUITARY SECRETION OF TSH", "token_count": 2007, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
It results from congenital lack of a thyroid gland (congenital cretinism), from failure of the thyroid gland to produce thyroid hormone because of a genetic defect of the gland, or from a lack of iodine in the diet (endemic cretinism). A neonate without a thyroid gland may have a normal appearance and function be...	{ "Header 1": "FEEDBACK EFFECT OF THYROID HORMONE TO DECREASE ANTERIOR PITUITARY SECRETION OF TSH", "token_count": 989, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The two adrenal glands, each of which weighs about 4 grams, lie at the superior poles of the two kidneys. As shown in [Figure 78-1](#page-903-0), each gland is composed of two major parts, the adrenal medulla and the adrenal cortex. The adrenal medulla, the central 20% of the gland, is functionally related to...	{ "Header 1": "Adrenocortical Hormones", "token_count": 1825, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### Mineralocorticoids - • Aldosterone (very potent; accounts for ≈90% of all mineralocorticoid activity) - • Deoxycorticosterone (1/30 as potent as aldosterone, but very small quantities are secreted) - • Corticosterone (slight mineralocorticoid activity) - • 9α-Fluorocortisol (synthetic; slightly more potent...	{ "Header 1": "Adrenocortical Hormones", "token_count": 1989, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### RENAL AND CIRCULATORY EFFECTS OF ALDOSTERONE Aldosterone Increases Renal Tubular Reabsorption of Sodium and Secretion of Potassium. As discussed in Chapter 28, aldosterone increases reabsorption of sodium and simultaneously increases secretion of potassium by the renal tubular epithelial cells, especia...	{ "Header 1": "Adrenocortical Hormones", "token_count": 2032, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Third, the aldosterone-receptor complex or a product of this complex diffuses into the nucleus, where it may undergo further alterations, finally inducing one or more specific portions of the DNA to form one or more types of messenger RNA (mRNA) related to the process of sodium and potassium transport. Fourth, the ...	{ "Header 1": "Adrenocortical Hormones", "token_count": 1997, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Cortisol causes mobilization of amino acids from extrahepatic tissues, mainly from muscle. As a result, more amino acids become available in the plasma to enter into the gluconeogenesis process of the liver and thereby to promote formation of glucose. - 3. *Cortisol antagonizes insulin's effects to inhibit gluconeoge...	{ "Header 1": "Adrenocortical Hormones", "token_count": 2040, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Also, the amino acids are perhaps used to synthesize other essential intracellular substances, such as purines, pyrimidines, and creatine phosphate, which are necessary for maintenance of cellular life and reproduction of new cells. All this is mainly supposition and is supported only by the fact that cortisol usuall...	{ "Header 1": "Adrenocortical Hormones", "token_count": 2015, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
When 11β-HSD2 is deficient, as in apparent mineralocorticoid excess syndrome due to genetic mutations or excessive licorice ingestion, or when circulating cortisol concentrations are extremely high, as in Cushing's syndrome, this mechanism for cortisol metabolism may be overwhelmed. As a result, the high levels of co...	{ "Header 1": "Adrenocortical Hormones", "token_count": 2032, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The gene that is transcribed to form the RNA molecule that causes ACTH synthesis initially causes formation of a considerably larger protein, a preprohormone called pro-opiomelanocortin (POMC), which is the precursor of ACTH and several other peptides, including melanocyte-stimulating hormone (MSH), *β-lipotropin, ...	{ "Header 1": "Adrenocortical Hormones", "token_count": 1986, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Leonard Posey.)* This critical need for extra glucocorticoids and the associated severe debility in times of acute stress is called an adrenal (or Addisonian) crisis. #### Hyperadrenalism—Cushing's Syndrome Hypersecretion by the adrenal cortex causes a complex cascade of hormone effects called *Cushing's ...	{ "Header 1": "Adrenocortical Hormones", "token_count": 2029, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Physiol Rev 93:1139, 2013. Dineen R, Stewart PM, Sherlock M: Factors impacting on the action of glucocorticoids in patients receiving glucocorticoid therapy. Clin Endocrinol (Oxf) 90:3, 2019. Feelders RA, Hofland LJ: Medical treatment of Cushing disease. J Clin Endocrinol Metab 98:425, 2013. - Funder JW: Primary ...	{ "Header 1": "Adrenocortical Hormones", "token_count": 811, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The pancreas, in addition to its digestive functions, secretes two major hormones, insulin and glucagon, that are crucial for normal regulation of glucose, lipid, and protein metabolism. Although the pancreas secretes other hormones, such as amylin, somatostatin, and pancreatic polypeptide, their functions are ...	{ "Header 1": "Insulin, Glucagon, and Diabetes Mellitus", "token_count": 2043, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
For example, glucose transporters are moved to the cell membrane to assist glucose entry into the cell. effects on carbohydrate, fat, and protein metabolism. The following are the main end effects of insulin stimulation: - 1. Within seconds after insulin binds with its membrane receptors, the membranes of about 80%...	{ "Header 1": "Insulin, Glucagon, and Diabetes Mellitus", "token_count": 370, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
During much of the day, muscle tissue depends not on glucose but on fatty acids for its energy. The principal reason for this dependence on fatty acids is that the normal resting muscle membrane is only slightly permeable to glucose, except when the muscle fiber is stimulated by insulin; between meals, the amount of ...	{ "Header 1": "Insulin, Glucagon, and Diabetes Mellitus", "Header 2": "Insulin Promotes Muscle Glucose Uptake and Metabolism", "token_count": 2031, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Insulin increases glucose transport into the liver cells. After the liver glycogen concentration reaches 5% to 6%, further glycogen synthesis is inhibited. All the additional glucose entering the liver cells then becomes available to form fat. The glucose is first split to pyruvate in the glycolytic pathway, and the ...	{ "Header 1": "Insulin, Glucagon, and Diabetes Mellitus", "Header 2": "Insulin Promotes Muscle Glucose Uptake and Metabolism", "token_count": 2010, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### Insulin and Growth Hormone Interact Synergistically to Promote Growth Because insulin is required for synthesis of proteins, it is as essential as growth hormone for the growth of an animal. As demonstrated in [Figure 79-6](#page-927-0), a depancreatized, hypophysectomized rat without replacement thera...	{ "Header 1": "Insulin, Glucagon, and Diabetes Mellitus", "Header 2": "Insulin Promotes Muscle Glucose Uptake and Metabolism", "token_count": 2031, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
As discussed later in the chapter, several drugs have been developed to mimic or enhance the actions of incretins for treatment of diabetes mellitus. #### Other Hormones and the Autonomic Nervous System. Other hormones that either directly increase insulin secretion or potentiate the glucose stimulus for insuli...	{ "Header 1": "Insulin, Glucagon, and Diabetes Mellitus", "Header 2": "Insulin Promotes Muscle Glucose Uptake and Metabolism", "token_count": 2005, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Thus, in hypoglycemia, glucagon is secreted in large amounts; it then greatly increases the output of glucose from the liver and thereby serves the important function of correcting the hypoglycemia. Increased Blood Amino Acids Stimulate Secretion of Glucagon. High concentrations of amino acids, such as those that...	{ "Header 1": "Insulin, Glucagon, and Diabetes Mellitus", "Header 2": "Insulin Promotes Muscle Glucose Uptake and Metabolism", "token_count": 2003, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Blood Glucose Concentration Rises to High Levels in Diabetes Mellitus. Lack of insulin decreases the efficiency of peripheral glucose utilization and augments glucose production, raising plasma glucose to 300 to 1200 mg/100 ml. The increased plasma glucose then has multiple adverse effects throughout the body. ...	{ "Header 1": "Insulin, Glucagon, and Diabetes Mellitus", "Header 2": "Insulin Promotes Muscle Glucose Uptake and Metabolism", "token_count": 2035, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### TABLE 79-2 Some Causes of Insulin Resistance - • Obesity/overweight (especially excess visceral adiposity) - • Excess glucocorticoids (Cushing's syndrome or steroid therapy) - • Excess growth hormone (acromegaly) - • Pregnancy, gestational diabetes - • Polycystic ovary disease - • Lipodystrophy (acquired o...	{ "Header 1": "Insulin, Glucagon, and Diabetes Mellitus", "Header 2": "Insulin Promotes Muscle Glucose Uptake and Metabolism", "token_count": 2007, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Glycated Hemoglobin. When blood glucose levels are elevated for prolonged periods of time, glucose attaches to ![](_page_936_Figure_1.jpeg) Figure 79-12. Glucose tolerance curve in a normal person and in a person with diabetes. hemoglobin in red blood cells to form glycated hemoglobin, often called *h...	{ "Header 1": "Insulin, Glucagon, and Diabetes Mellitus", "Header 2": "Insulin Promotes Muscle Glucose Uptake and Metabolism", "token_count": 2021, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Cell 172(1-2):22, 2018. - Mann JP, Savage DB: What lipodystrophies teach us about the metabolic syndrome. J Clin Invest 130:4009, 2019. - Müller TD, Finan B, Clemmensen C, et al: The new biology and pharmacology of glucagon. Physiol Rev 97:721, 2017. - Oram RA, Sims EK, Evans-Molina C: Beta cells in type 1 diabetes: ma...	{ "Header 1": "Insulin, Glucagon, and Diabetes Mellitus", "Header 2": "Insulin Promotes Muscle Glucose Uptake and Metabolism", "token_count": 518, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The physiology of calcium and phosphate metabolism, formation of bone and teeth, and regulation of vitamin D, parathyroid hormone (PTH), and calcitonin are all closely intertwined. The extracellular calcium ion concentration, for example, is determined by the interplay of calcium absorption from the intestine, rena...	{ "Header 1": "Insulin, Glucagon, and Diabetes Mellitus", "Header 2": "Parathyroid Hormone, Calcitonin, Calcium and Phosphate Metabolism, Vitamin D, Bone, and Teeth", "token_count": 1087, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Changing the level of phosphate in the extracellular fluid from far below normal to two to three times normal does not cause major immediate effects on the body. In contrast, even slight increases or decreases of calcium ion in the extracellular fluid can cause extreme immediate physiological effects. In addition, chro...	{ "Header 1": "NONBONE PHYSIOLOGICAL EFFECTS OF ALTERED CALCIUM AND PHOSPHATE CONCENTRATIONS IN THE BODY FLUIDS", "token_count": 577, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Intestinal Absorption and Fecal Excretion of Calcium and Phosphate. The usual rates of intake are approximately 1000 mg/day each for calcium and phosphorus, about the amounts in 1 liter of milk. Normally, divalent cations such as calcium ions are poorly absorbed from the intestines. However, as discussed later, *vitami...	{ "Header 1": "NONBONE PHYSIOLOGICAL EFFECTS OF ALTERED CALCIUM AND PHOSPHATE CONCENTRATIONS IN THE BODY FLUIDS", "Header 2": "ABSORPTION AND EXCRETION OF CALCIUM AND PHOSPHATE", "token_count": 2042, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The collagen monomers polymerize rapidly to form collagen fibers; the resultant tissue becomes osteoid, a cartilage-like material differing from cartilage in that calcium salts readily precipitate in it. As the osteoid is formed, some of the osteoblasts become entrapped in the osteoid and become quiescent. At this st...	{ "Header 1": "NONBONE PHYSIOLOGICAL EFFECTS OF ALTERED CALCIUM AND PHOSPHATE CONCENTRATIONS IN THE BODY FLUIDS", "Header 2": "ABSORPTION AND EXCRETION OF CALCIUM AND PHOSPHATE", "token_count": 2013, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
OPG acts as a "decoy," binding to RANKL and preventing it from interacting with its receptor, thereby inhibiting differentiation of preosteoclasts into mature osteoclasts that resorb bone. OPG opposes the bone resorptive activity of PTH, and mice with a genetic deficiency of OPG have severe decreases in bone mass compa...	{ "Header 1": "NONBONE PHYSIOLOGICAL EFFECTS OF ALTERED CALCIUM AND PHOSPHATE CONCENTRATIONS IN THE BODY FLUIDS", "Header 2": "ABSORPTION AND EXCRETION OF CALCIUM AND PHOSPHATE", "token_count": 2006, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
This latter substance is by far the most active form of vitamin D because the previous products in the scheme of [Figure 80-8](#page-944-1) have less than 1/1000 of the vitamin D effect. Therefore, in the absence of the kidneys, vitamin D loses almost all its effectiveness. Note also in **[Figure 80-8](#page-944-...	{ "Header 1": "NONBONE PHYSIOLOGICAL EFFECTS OF ALTERED CALCIUM AND PHOSPHATE CONCENTRATIONS IN THE BODY FLUIDS", "Header 2": "ABSORPTION AND EXCRETION OF CALCIUM AND PHOSPHATE", "token_count": 2039, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The final hormone has a molecular weight of about 9500. Smaller compounds with as few as 34 amino acids adjacent to the N terminus of the molecule have also been isolated from the parathyroid glands that exhibit full PTH activity. In fact, because the kidneys rapidly remove the whole 84–amino acid hormone within minute...	{ "Header 1": "NONBONE PHYSIOLOGICAL EFFECTS OF ALTERED CALCIUM AND PHOSPHATE CONCENTRATIONS IN THE BODY FLUIDS", "Header 2": "ABSORPTION AND EXCRETION OF CALCIUM AND PHOSPHATE", "token_count": 2025, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
For example, the parathyroid glands become greatly enlarged in persons with rickets, in whom the calcium level is usually depressed only a small amount. These glands also become greatly enlarged during pregnancy, even though the decrease in calcium ion concentration in the mother's extracellular fluid is hardly mea...	{ "Header 1": "NONBONE PHYSIOLOGICAL EFFECTS OF ALTERED CALCIUM AND PHOSPHATE CONCENTRATIONS IN THE BODY FLUIDS", "Header 2": "ABSORPTION AND EXCRETION OF CALCIUM AND PHOSPHATE", "token_count": 2044, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Conversely, a decrease in these concentrations causes immediate absorption of exchangeable salt. This reaction is rapid because the amorphous bone crystals are extremely small and their total surface area exposed to the fluids of the bone is large—perhaps 1 acre or more. In addition, about 5% of all the blood flows t...	{ "Header 1": "NONBONE PHYSIOLOGICAL EFFECTS OF ALTERED CALCIUM AND PHOSPHATE CONCENTRATIONS IN THE BODY FLUIDS", "Header 2": "ABSORPTION AND EXCRETION OF CALCIUM AND PHOSPHATE", "token_count": 2004, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Secondary hyperparathyroidism can be caused by vitamin D deficiency or chronic renal disease in which the damaged kidneys are unable to produce sufficient amounts of the active form of vitamin D, 1,25-dihydroxycholecalciferol. As discussed in more detail in the next section, the vitamin D deficiency leads to *osteoma...	{ "Header 1": "NONBONE PHYSIOLOGICAL EFFECTS OF ALTERED CALCIUM AND PHOSPHATE CONCENTRATIONS IN THE BODY FLUIDS", "Header 2": "ABSORPTION AND EXCRETION OF CALCIUM AND PHOSPHATE", "token_count": 2046, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Many collagen fibers pass directly from the bone of the jaw, through the periodontal membrane, and then into the cementum. These collagen fibers and the cementum hold the tooth in place. When the teeth are exposed to excessive strain, the layer of cementum becomes thicker and stronger. Also, it increases in thickness a...	{ "Header 1": "NONBONE PHYSIOLOGICAL EFFECTS OF ALTERED CALCIUM AND PHOSPHATE CONCENTRATIONS IN THE BODY FLUIDS", "Header 2": "ABSORPTION AND EXCRETION OF CALCIUM AND PHOSPHATE", "token_count": 2023, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### Bibliography Bilezikian JP, Bandeira L, Khan A, Cusano NE: Hyperparathyroidism. Lancet 391:168, 2018. Chande S, Bergwitz C: Role of phosphate sensing in bone and mineral metabolism. Nat Rev Endocrinol 14:637, 2018. Christakos S, Dhawan P, Verstuyf A, et al: Vitamin D: metabolism, molecular mechanism of act...	{ "Header 1": "NONBONE PHYSIOLOGICAL EFFECTS OF ALTERED CALCIUM AND PHOSPHATE CONCENTRATIONS IN THE BODY FLUIDS", "Header 2": "ABSORPTION AND EXCRETION OF CALCIUM AND PHOSPHATE", "token_count": 845, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Male reproductive functions can be divided into three major subdivisions: (1) formation of sperm—spermatogenesis; (2) performance of the male sexual act; and (3) regulation of male reproductive functions by the various hormones. Associated with these reproductive functions are the effects of the male sex hormones on th...	{ "Header 1": "Reproductive and Hormonal Functions of the Male (and Function of the Pineal Gland)", "token_count": 2045, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Luteinizing hormone, secreted by the anterior pituitary gland, stimulates the Leydig cells to secrete testosterone. - 3. Follicle-stimulating hormone, also secreted by the anterior pituitary gland, stimulates the Sertoli cells; without this stimulation, conversion of the spermatids to sperm (the process of spermi...	{ "Header 1": "Reproductive and Hormonal Functions of the Male (and Function of the Pineal Gland)", "token_count": 2032, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Without these changes, the sperm cannot make its way to the interior of the ovum to cause fertilization. #### Acrosome Enzymes, the "Acrosome Reaction," and Penetration of the Ovum Stored in the acrosome of the sperm are large quantities of hyaluronidase and proteolytic enzymes. Hyaluronidase depolymerizes ...	{ "Header 1": "Reproductive and Hormonal Functions of the Male (and Function of the Pineal Gland)", "token_count": 1990, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### Integration of the Male Sexual Act in the Spinal Cord. Although psychic factors usually play an important part in the male sexual act and can initiate or inhibit it, brain function is probably not necessary for its performance ![](_page_963_Picture_2.jpeg) Figure 81-6 Erectile tissue of the penis. ...	{ "Header 1": "Reproductive and Hormonal Functions of the Male (and Function of the Pineal Gland)", "token_count": 1998, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Degradation and Excretion of Testosterone. The testosterone that does not become fixed to the tissues is rapidly converted, mainly by the liver, into androsterone and dehydroepiandrosterone and simultaneously conjugated as either glucuronides or sulfates (glucuronides, particularly). These substances are excr...	{ "Header 1": "Reproductive and Hormonal Functions of the Male (and Function of the Pineal Gland)", "token_count": 1983, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Testosterone has a specific effect on the pelvis to (1) narrow the pelvic outlet, (2) lengthen it, (3) cause a funnel-like shape instead of the broad ovoid shape of the female pelvis, and (4) greatly increase the strength of the entire pelvis for load bearing. In the absence of testosterone, the male pelvis develops ...	{ "Header 1": "Reproductive and Hormonal Functions of the Male (and Function of the Pineal Gland)", "token_count": 2008, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### Regulation of Spermatogenesis by Follicle-Stimulating Hormone and Testosterone FSH binds with specific FSH receptors attached to the Sertoli cells in the seminiferous tubules, which causes the Sertoli cells to grow and secrete various spermatogenic substances. Simultaneously, testosterone (and dihydrotesto...	{ "Header 1": "Reproductive and Hormonal Functions of the Male (and Function of the Pineal Gland)", "token_count": 1999, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### Erectile Dysfunction in the Male Erectile dysfunction, also called "impotence," is characterized by an inability of the man to develop or maintain an erection of sufficient rigidity for satisfactory sexual intercourse. Neurological problems, such as trauma to the parasympathetic nerves from prostate surg...	{ "Header 1": "Reproductive and Hormonal Functions of the Male (and Function of the Pineal Gland)", "token_count": 1743, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Female reproductive functions can be divided into two major phases: (1) preparation of the female body for conception and pregnancy and (2) the period of pregnancy itself. This chapter is concerned with preparation of the female body for pregnancy, and Chapter 83 presents the physiology of pregnancy and childbirth. #...	{ "Header 1": "Female Physiology Before Pregnancy and Female Hormones", "token_count": 2015, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### OVARIAN FOLLICLE GROWTH—THE FOLLICULAR PHASE OF THE OVARIAN CYCLE [Figure 82-5](#page-975-0) shows the progressive stages of follicular growth in the ovaries. When a female child is born, ![](_page_975_Picture_1.jpeg) Figure 82-5. Stages of follicular growth in the ovary, also showing formation...	{ "Header 1": "Female Physiology Before Pregnancy and Female Hormones", "token_count": 2003, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
This process is called luteinization, and the total mass of cells together is called the corpus luteum, which is shown in [Figure 82-5](#page-975-0). A well-developed vascular supply also grows into the corpus luteum. The granulosa cells in the corpus luteum develop extensive intracellular smooth endoplasmi...	{ "Header 1": "Female Physiology Before Pregnancy and Female Hormones", "token_count": 2028, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The theca cells, under the control of luteinizing hormone (LH), produce androgens that diffuse into the granulosa cells. In mature follicles, follicle-stimulating hormone (FSH) acts on granulosa cells to stimulate aromatase activity, which converts the androgens to estrogens. AC, Adenylate cyclase; ATP, adenosine triph...	{ "Header 1": "Female Physiology Before Pregnancy and Female Hormones", "token_count": 507, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
A primary function of the estrogens is to cause cellular proliferation and growth of the tissues of the sex organs and other tissues related to reproduction. Effect of Estrogens on the Uterus and External Female Sex Organs. During childhood, estrogens are secreted only in minute quantities, but at puberty, the quanti...	{ "Header 1": "FUNCTIONS OF THE ESTROGENS—THEIR EFFECTS ON THE PRIMARY AND SECONDARY FEMALE SEX CHARACTERISTICS", "token_count": 2017, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
After menstruation, only a thin layer of endometrial stroma remains, and the only epithelial cells that are left are those located in the remaining deeper portions of the glands and crypts of the endometrium. Under the influence of estrogens, secreted in increasing quantities by the ovary during the first part of the...	{ "Header 1": "FUNCTIONS OF THE ESTROGENS—THEIR EFFECTS ON THE PRIMARY AND SECONDARY FEMALE SEX CHARACTERISTICS", "token_count": 2005, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### NEGATIVE FEEDBACK EFFECTS OF ESTROGEN AND PROGESTERONE TO DECREASE LH AND FSH SECRETION Estrogen in small amounts has a strong inhibitory effect on production of LH and FSH. Also, when progesterone is available, the inhibitory effect of estrogen is multiplied, even though progesterone by itself has little ...	{ "Header 1": "FUNCTIONS OF THE ESTROGENS—THEIR EFFECTS ON THE PRIMARY AND SECONDARY FEMALE SEX CHARACTERISTICS", "token_count": 2040, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
In the female, as in the male, the infantile pituitary gland and ovaries are capable of full function if they are appropriately stimulated. However, as is also true in the male, and for reasons that are not understood, the hypothalamus does not secrete significant quantities of GnRH during childhood. Experiments have...	{ "Header 1": "FUNCTIONS OF THE ESTROGENS—THEIR EFFECTS ON THE PRIMARY AND SECONDARY FEMALE SEX CHARACTERISTICS", "token_count": 2014, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Female Orgasm. When local sexual stimulation reaches maximum intensity, and especially when the local sensations are supported by appropriate psychic conditioning signals from the cerebrum, reflexes are initiated that cause the female orgasm, also called the female climax. The female orgasm is analogous to emis...	{ "Header 1": "FUNCTIONS OF THE ESTROGENS—THEIR EFFECTS ON THE PRIMARY AND SECONDARY FEMALE SEX CHARACTERISTICS", "token_count": 2043, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Another common cause of female infertility is salpingitis, that is, inflammation of the fallopian tubes; this inflammation causes fibrosis in the tubes, thereby occluding them. In the past, such inflammation occurred mainly as a result of gonococcal infection. However, with modern therapy, salpingitis is becoming...	{ "Header 1": "FUNCTIONS OF THE ESTROGENS—THEIR EFFECTS ON THE PRIMARY AND SECONDARY FEMALE SEX CHARACTERISTICS", "token_count": 1059, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
In Chapters 81 and 82, the sexual functions of the male and female are described to the point of fertilization of the ovum. If the ovum becomes fertilized, a new sequence of events called gestation or pregnancy takes place, and the fertilized ovum eventually develops into a full-term fetus. The purpose of this chap...	{ "Header 1": "Pregnancy and Lactation", "token_count": 1234, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
After fertilization has occurred, an additional 3 to 5 days is normally required for transport of the fertilized ovum through the remainder of the fallopian tube into the cavity of the uterus (Figure 83-2). This transport is effected mainly by a feeble fluid current in the tube resulting from epithelial secretion p...	{ "Header 1": "Pregnancy and Lactation", "Header 2": "TRANSPORT OF THE FERTILIZED OVUM IN THE FALLOPIAN TUBE", "token_count": 402, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
After reaching the uterus, the developing blastocyst usually remains in the uterine cavity an additional 1 to 3 days before it implants in the endometrium; thus, implantation ordinarily occurs on about the fifth to seventh day after ovulation. Before implantation, the blastocyst obtains its nutrition from the uterine e...	{ "Header 1": "Pregnancy and Lactation", "Header 2": "IMPLANTATION OF THE BLASTOCYST IN THE UTERUS", "token_count": 597, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
While the trophoblastic cords from the blastocyst are attaching to the uterus, blood capillaries grow into the cords from the vascular system of the newly forming embryo. About 21 days after fertilization, blood also ![](_page_992_Figure_10.jpeg) Figure 83-4. Nutrition of the fetus. Most of the early nutrition ...	{ "Header 1": "Pregnancy and Lactation", "Header 2": "ANATOMY AND FUNCTION OF THE PLACENTA", "token_count": 442, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The major function of the placenta is to provide for diffusion of foodstuffs and oxygen from the mother's blood into the fetus's blood and diffusion of excretory products from the fetus back into the mother. In the early months of pregnancy, the placental membrane is still thick because it is not fully developed. The...	{ "Header 1": "Pregnancy and Lactation", "Header 2": "PLACENTAL PERMEABILITY AND MEMBRANE DIFFUSION CONDUCTANCE", "token_count": 2043, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Then, the secretion rate rises rapidly to reach a maximum at about 10 to 12 weeks of pregnancy and decreases back to a lower value by 16 to 20 weeks. It continues at this level for the remainder of the pregnancy. Function of Human Chorionic Gonadotropin. Human chorionic gonadotropin is a glycoprotein having a mol...	{ "Header 1": "Pregnancy and Lactation", "Header 2": "PLACENTAL PERMEABILITY AND MEMBRANE DIFFUSION CONDUCTANCE", "token_count": 2024, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
It is possible that these glucocorticoids help mobilize amino acids from the mother's tissues to be used for synthesis of fetal tissues. Pregnant women usually have about a 2-fold increase in aldosterone secretion, reaching a peak at the end of gestation. This increase, along with the actions of estrogens, causes...	{ "Header 1": "Pregnancy and Lactation", "Header 2": "PLACENTAL PERMEABILITY AND MEMBRANE DIFFUSION CONDUCTANCE", "token_count": 2025, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Second, the renal blood flow and glomerular filtration rate increase up to 50% during normal pregnancy as a result of renal vasodilation. Although the mechanisms that cause renal vasodilation in pregnancy are still unclear, some studies suggest that increased levels of nitric oxide or the ovarian hormone relaxin ma...	{ "Header 1": "Pregnancy and Lactation", "Header 2": "PLACENTAL PERMEABILITY AND MEMBRANE DIFFUSION CONDUCTANCE", "token_count": 2014, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Note especially that twins are born, on average, 19 days earlier than a single child, which emphasizes the importance of mechanical stretch in eliciting uterine contractions. Stretch or Irritation of the Cervix. There is reason to believe that stretching or irritating the uterine cervix is particularly importan...	{ "Header 1": "Pregnancy and Lactation", "Header 2": "PLACENTAL PERMEABILITY AND MEMBRANE DIFFUSION CONDUCTANCE", "token_count": 2026, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
During early involution of the uterus, the placental site on the endometrial surface autolyzes, causing a vaginal discharge known as lochia, which is first bloody and then serous in nature and continues for a total of about 10 days. After this time, the endometrial surface becomes reepithelialized and ready for norma...	{ "Header 1": "Pregnancy and Lactation", "Header 2": "PLACENTAL PERMEABILITY AND MEMBRANE DIFFUSION CONDUCTANCE", "token_count": 1804, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Milk is secreted continuously into the alveoli of the breasts, but it does not flow easily from the alveoli into the ductal system and, therefore, does not continually leak from the nipples. Instead, the milk must be ejected from the alveoli into the ducts before the baby can obtain it. This ejection is caused by a c...	{ "Header 1": "EJECTION (OR \"LET-DOWN\") PROCESS IN MILK SECRETION—FUNCTION OF OXYTOCIN", "token_count": 1912, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
A complete discussion of fetal development, physiology of the child immediately after birth, and growth and development through the early years of life lies within the province of formal courses in obstetrics and pediatrics. However, many physiological principles are peculiar to the infant, and this chapter discusses t...	{ "Header 1": "Fetal and Neonatal Physiology", "token_count": 2031, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
In its absence in laboratory animals, spontaneous abortion usually occurs at an early stage of pregnancy. Vitamin K is used by the fetal liver for formation of Factor VII, prothrombin, and several other blood coagulation factors. When vitamin K is insufficient in the mother, Factor VII and prothrombin become deficien...	{ "Header 1": "Fetal and Neonatal Physiology", "token_count": 2001, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
It is pumped by the right ventricle into the pulmonary artery and then mainly through the ductus arteriosus into the descending aorta, then through the two umbilical arteries into the placenta, where the deoxygenated blood becomes oxygenated. [Figure 84-5](#page-1009-0) shows the relative percentages of the tot...	{ "Header 1": "Fetal and Neonatal Physiology", "token_count": 2006, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Cardiac Output. The cardiac output of the neonate averages 500 ml/min, which, like respiration and body metabolism, is about twice as much in relation to body weight as in the adult. Occasionally a child is born with an especially low cardiac output caused by hemorrhage of much of its blood volume from the placen...	{ "Header 1": "Fetal and Neonatal Physiology", "token_count": 2040, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
This is particularly true in premature babies because their gastrointestinal tracts absorb calcium even less effectively than do those of normal infants. Need for Iron in the Diet. If the mother has had adequate amounts of iron in her diet, the infant's liver usually has stored enough iron to keep forming blood c...	{ "Header 1": "Fetal and Neonatal Physiology", "token_count": 2035, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The premature infant's temperature tends to approach that of its surroundings. At normal room temperature, the infant's temperature (in degrees Fahrenheit) may stabilize in the low 90s or even in the 80s. Studies show that a body temperature maintained below 96°F (35.5°C) is associated with a particularly high incidenc...	{ "Header 1": "Fetal and Neonatal Physiology", "token_count": 1779, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
There are few stresses to which the body is exposed that approach the extreme stresses of heavy exercise. In fact, if some of the extremes of exercise were continued for even moderately prolonged periods, they might be lethal. Therefore, sports physiology is mainly a discussion of the ultimate limits to which several o...	{ "Header 1": "Sports Physiology", "token_count": 1969, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The amounts stored are approximately the following: \| \| g/kg Muscle \| \|------------------------\|-------------\| \| High-carbohydrate diet \| 40 \| \| Mixed diet \| 20 \| \| High-fat diet \| 6 \| #### Muscle Metabolic Systems in Exercise The same ba...	{ "Header 1": "Sports Physiology", "token_count": 2009, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }

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Therefore, conduction of heat from the body to the air is self-limited unless the heated air moves away from the skin, so new, unheated air is continually brought in contact with the skin, a phenomenon called air convection. Convective Heat Loss Results From Air Movement. Heat from the skin is first *conducte...	{ "Header 1": "Body Temperature Regulation and Fever", "token_count": 1995, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Acclimatization of the Sweating Mechanism to Heat—The Role of Aldosterone. Although a normal, unacclimatized person seldom produces more than about 1 liter of sweat per hour, when this person is exposed to hot weather for 1 to 6 weeks, he or she begins to sweat more profusely, often increasing maximum sweat produ...	{ "Header 1": "Body Temperature Regulation and Fever", "token_count": 2034, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Skin vasoconstriction throughout the body. This vasoconstriction is caused by stimulation of the posterior hypothalamic sympathetic centers. - 2. Piloerection. Piloerection means hairs "standing on end." Sympathetic stimulation causes the arrector ![](_page_859_Figure_2.jpeg) Figure 74-7. Effect of hypothal...	{ "Header 1": "Body Temperature Regulation and Fever", "token_count": 1336, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
In the example of Figure 74-7, it is clear that at a critical body core temperature of about 37.1°C (98.8°F), drastic changes occur in the rates of both heat loss and heat production. At temperatures above this level, the rate of heat loss is greater than that of heat production, so the body temperature falls and a...	{ "Header 1": "Body Temperature Regulation and Fever", "Header 2": "\"SET POINT\" FOR TEMPERATURE CONTROL", "token_count": 919, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Aside from the subconscious mechanisms for body temperature control, the body has another temperature-control mechanism that is even more potent—behavioral control of temperature. Whenever the internal body temperature becomes too high, signals from the temperature-controlling areas in the brain give the person a psy...	{ "Header 1": "Body Temperature Regulation and Fever", "Header 2": "BEHAVIORAL CONTROL OF BODY TEMPERATURE", "token_count": 517, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### FEVER Fever, which means a body temperature above the usual range of normal, can be caused by abnormalities in the brain or by toxic substances that affect the temperature-regulating centers. Some causes of fever (and also of subnormal body temperatures) are presented in Figure 74-10. They include bacter...	{ "Header 1": "Body Temperature Regulation and Fever", "Header 2": "ABNORMALITIES OF BODY TEMPERATURE REGULATION", "token_count": 2040, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### Exposure of the Body to Extreme Cold Unless treated immediately, a person exposed to ice water for 20 to 30 minutes ordinarily dies because of heart standstill or heart fibrillation. By that time, the internal body temperature will have fallen to about 77°F. If warmed rapidly by the application of external...	{ "Header 1": "Body Temperature Regulation and Fever", "Header 2": "ABNORMALITIES OF BODY TEMPERATURE REGULATION", "token_count": 1352, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### COORDINATION OF BODY FUNCTIONS BY CHEMICAL MESSENGERS The multiple activities of the cells, tissues, and organs of the body are coordinated by the interplay of several types of chemical messenger systems: - 1. Neurotransmitters are released by axon terminals of neurons into the synaptic junctions and act loc...	{ "Header 1": "Introduction to Endocrinology", "token_count": 1812, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Hormone secretion occurs when the amines are split from Table 75-1 Endocrine Glands, Hormones, and Their Functions and Structure \| Gland/Tissue \| Hormones \| Major Functions ...	{ "Header 1": "Introduction to Endocrinology", "token_count": 2019, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Concentrations of Hormones in the Circulating Blood and Hormonal Secretion Rates. The concentrations of hormones required to control most metabolic and endocrine functions are incredibly small. Their concentrations in the blood range from as little as 1 picogram (which is one millionth of one millionth of a gram)...	{ "Header 1": "Introduction to Endocrinology", "token_count": 2024, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The Number and Sensitivity of Hormone Receptors Are Regulated. The number of receptors in a target cell usually does not remain constant from day to day or even from minute to minute. Receptor proteins are often inactivated or destroyed during the course of their function, and at other times they are reactivated ...	{ "Header 1": "Introduction to Endocrinology", "token_count": 2029, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
JAK2 phosphorylation also activates several other enzyme systems that mediate some of the more rapid effects of leptin. Y, Specific tyrosine phosphorylation sites. special transmembrane receptor, which then becomes the activated enzyme adenylyl cyclase at the end that protrudes to the interior of the cell. This cyc...	{ "Header 1": "Introduction to Endocrinology", "token_count": 2040, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### Calcium-Calmodulin Second Messenger System Another second messenger system operates in response to entry of calcium into the cells. Calcium entry may be initiated by (1) changes in membrane potential that open calcium channels or (2) a hormone interacting with membrane receptors that open calcium channels....	{ "Header 1": "Introduction to Endocrinology", "token_count": 2042, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The amount of the product is measured using optical methods and is proportional to the amount of hormone in the well if there are excess antibodies in the well. #### Bibliography Aguiar-Oliveira MH, Bartke A: Growth hormone deficiency: health and longevity. Endocr Rev 40:575, 2019. Baker ME: Steroid receptors and...	{ "Header 1": "Introduction to Endocrinology", "token_count": 906, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### PITUITARY GLAND AND ITS RELATION TO THE HYPOTHALAMUS #### ANTERIOR AND POSTERIOR LOBES OF THE PITUITARY GLAND The pituitary gland ([Figure 76-1](#page-878-0)), also called the hypophysis, is a small gland—about 1 centimeter in diameter and 0.5 to 1 gram in weight—that lies in the sella turcica, a...	{ "Header 1": "Pituitary Hormones and Their Control by the Hypothalamus", "token_count": 1351, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Almost all pituitary secretion is controlled by hormonal or nervous signals from the hypothalamus. Indeed, when the pituitary gland is removed from its normal position beneath the hypothalamus and transplanted to some other part of the body, its secretion rates of the different hormones (except for prolactin) fall to v...	{ "Header 1": "Pituitary Hormones and Their Control by the Hypothalamus", "Header 2": "HYPOTHALAMUS CONTROLS PITUITARY SECRETION", "token_count": 2034, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Specific Areas in the Hypothalamus Control Secretion of Specific Hypothalamic Releasing and Inhibitory Hormones. All or most of the hypothalamic hormones are secreted at nerve endings in the median eminence before being transported to the anterior pituitary gland. Electrical stimulation of this region excites the...	{ "Header 1": "Pituitary Hormones and Their Control by the Hypothalamus", "Header 2": "HYPOTHALAMUS CONTROLS PITUITARY SECRETION", "token_count": 897, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Over more prolonged periods (24–48 hours), GH also stimulates transcription of DNA in the nucleus, causing formation of increased quantities of RNA. This promotes more ![](_page_882_Figure_12.jpeg) Figure 76-6. Effects of growth hormone and insulin-like growth factor -1 (IGF-1) on growth and metabolism. Growth ...	{ "Header 1": "Pituitary Hormones and Their Control by the Hypothalamus", "Header 2": "Increased Nuclear Transcription of DNA to Form RNA.", "token_count": 2043, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
One possible explanation for this finding is that GH can cause formation of enough IGF-1 in the local tissue to cause local growth. However, GH also has IGF-independent effects that stimulate growth in some tissues such as chondrocytes of cartilage. **Short Duration of Action of Growth Hormone but Prolonged Action of...	{ "Header 1": "Pituitary Hormones and Their Control by the Hypothalamus", "Header 2": "Increased Nuclear Transcription of DNA to Form RNA.", "token_count": 1999, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Thus, the picture is that of a lethargic person (from lack of thyroid hormones) who is gaining weight (because of lack of fat mobilization by growth, adrenocorticotropic, adrenocortical, and thyroid hormones) and has lost all sexual functions. Except for the abnormal sexual functions, the patient can usually be treated...	{ "Header 1": "Pituitary Hormones and Their Control by the Hypothalamus", "Header 2": "Increased Nuclear Transcription of DNA to Form RNA.", "token_count": 2045, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Their amino acid sequences are the following: Vasopressin: Cys-Tyr-Phe-Gln-Asn-Cys-Pro-Arg-GlyNH2 Oxytocin: Cys-Tyr-Ile-Gln-Asn-Cys-Pro-Leu-GlyNH<sup>2</sup> Note that these two hormones are almost identical except that in vasopressin, phenylalanine and arginine replace isoleucine and leucine of the oxytoci...	{ "Header 1": "Pituitary Hormones and Their Control by the Hypothalamus", "Header 2": "Increased Nuclear Transcription of DNA to Form RNA.", "token_count": 1993, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Physiol Rev 98:2225, 2018. - Freeman ME, Kanyicska B, Lerant A, Nagy G: Prolactin: structure, function, and regulation of secretion. Physiol Rev 80:1523, 2000. - Gimpl G, Fahrenholz F: The oxytocin receptor system: structure, function, and regulation. Physiol Rev 81:629, 2001. - Hannon AM, Thompson CJ, Sherlock M: Diab...	{ "Header 1": "Pituitary Hormones and Their Control by the Hypothalamus", "Header 2": "Increased Nuclear Transcription of DNA to Form RNA.", "token_count": 560, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The thyroid gland, located immediately below the larynx on each side of and anterior to the trachea, is one of the largest of the endocrine glands, normally weighing 15 to 20 grams in adults. The thyroid secretes two major metabolic hormones, thyroxine and triiodothyronine, commonly called T4 and T3, respective...	{ "Header 1": "Thyroid Metabolic Hormones", "token_count": 1237, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Formation and Secretion of Thyroglobulin by the Thyroid Cells. The thyroid cells are typical protein-secreting glandular cells, as shown in Figure 77-2. The endoplasmic reticulum and Golgi apparatus synthesize and secrete into the follicles a large glycoprotein molecule called thyroglobulin, with a molecular weight o...	{ "Header 1": "Thyroid Metabolic Hormones", "Header 2": "THYROGLOBULIN AND FORMATION OF THYROXINE AND TRIIODOTHYRONINE", "token_count": 2041, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Half the thyroxine in the blood is released to the tissue cells about every 6 days, whereas half the triiodothyronine—because of its lower affinity—is released to the cells in about 1 day. Upon entering the tissue cells, both thyroxine and triiodothyronine again bind with intracellular proteins, with the thyroxine bi...	{ "Header 1": "Thyroid Metabolic Hormones", "Header 2": "THYROGLOBULIN AND FORMATION OF THYROXINE AND TRIIODOTHYRONINE", "token_count": 2035, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Effect on Plasma and Liver Fats. Increased thyroid hormone decreases the concentrations of cholesterol, phospholipids, and triglycerides in the plasma, even though it increases the free fatty acids. Conversely, decreased thyroid secretion greatly increases the plasma concentrations of cholesterol, phosp...	{ "Header 1": "Thyroid Metabolic Hormones", "Header 2": "THYROGLOBULIN AND FORMATION OF THYROXINE AND TRIIODOTHYRONINE", "token_count": 2035, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Increased activity of the iodide pump, which increases the rate of "iodide trapping" in the glandular cells, sometimes increasing the ratio of intracellular to extracellular iodide concentration in the glandular substance to as much as eight times normal - 3. Increased iodination of tyrosine to form the thyroid hor...	{ "Header 1": "Thyroid Metabolic Hormones", "Header 2": "THYROGLOBULIN AND FORMATION OF THYROXINE AND TRIIODOTHYRONINE", "token_count": 1159, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Increased thyroid hormone in the body fluids decreases TSH secretion by the anterior pituitary. When the rate of thyroid hormone secretion rises to about 1.75 times normal, the rate of TSH secretion falls essentially to zero. Almost all this feedback depressant effect occurs even when the anterior pituitary has been se...	{ "Header 1": "FEEDBACK EFFECT OF THYROID HORMONE TO DECREASE ANTERIOR PITUITARY SECRETION OF TSH", "token_count": 1999, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
In the usual type of thyrotoxicosis, anterior pituitary secretion of TSH is so completely sup- - pressed by the large amounts of circulating thyroxine and triiodothyronine that there is almost no plasma TSH. - 3. The concentration of TSI is measured by immunoassay. This concentration is usually high in thyrotoxicosis...	{ "Header 1": "FEEDBACK EFFECT OF THYROID HORMONE TO DECREASE ANTERIOR PITUITARY SECRETION OF TSH", "token_count": 2007, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
It results from congenital lack of a thyroid gland (congenital cretinism), from failure of the thyroid gland to produce thyroid hormone because of a genetic defect of the gland, or from a lack of iodine in the diet (endemic cretinism). A neonate without a thyroid gland may have a normal appearance and function be...	{ "Header 1": "FEEDBACK EFFECT OF THYROID HORMONE TO DECREASE ANTERIOR PITUITARY SECRETION OF TSH", "token_count": 989, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The two adrenal glands, each of which weighs about 4 grams, lie at the superior poles of the two kidneys. As shown in [Figure 78-1](#page-903-0), each gland is composed of two major parts, the adrenal medulla and the adrenal cortex. The adrenal medulla, the central 20% of the gland, is functionally related to...	{ "Header 1": "Adrenocortical Hormones", "token_count": 1825, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### Mineralocorticoids - • Aldosterone (very potent; accounts for ≈90% of all mineralocorticoid activity) - • Deoxycorticosterone (1/30 as potent as aldosterone, but very small quantities are secreted) - • Corticosterone (slight mineralocorticoid activity) - • 9α-Fluorocortisol (synthetic; slightly more potent...	{ "Header 1": "Adrenocortical Hormones", "token_count": 1989, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### RENAL AND CIRCULATORY EFFECTS OF ALDOSTERONE Aldosterone Increases Renal Tubular Reabsorption of Sodium and Secretion of Potassium. As discussed in Chapter 28, aldosterone increases reabsorption of sodium and simultaneously increases secretion of potassium by the renal tubular epithelial cells, especia...	{ "Header 1": "Adrenocortical Hormones", "token_count": 2032, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Third, the aldosterone-receptor complex or a product of this complex diffuses into the nucleus, where it may undergo further alterations, finally inducing one or more specific portions of the DNA to form one or more types of messenger RNA (mRNA) related to the process of sodium and potassium transport. Fourth, the ...	{ "Header 1": "Adrenocortical Hormones", "token_count": 1997, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Cortisol causes mobilization of amino acids from extrahepatic tissues, mainly from muscle. As a result, more amino acids become available in the plasma to enter into the gluconeogenesis process of the liver and thereby to promote formation of glucose. - 3. *Cortisol antagonizes insulin's effects to inhibit gluconeoge...	{ "Header 1": "Adrenocortical Hormones", "token_count": 2040, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Also, the amino acids are perhaps used to synthesize other essential intracellular substances, such as purines, pyrimidines, and creatine phosphate, which are necessary for maintenance of cellular life and reproduction of new cells. All this is mainly supposition and is supported only by the fact that cortisol usuall...	{ "Header 1": "Adrenocortical Hormones", "token_count": 2015, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
When 11β-HSD2 is deficient, as in apparent mineralocorticoid excess syndrome due to genetic mutations or excessive licorice ingestion, or when circulating cortisol concentrations are extremely high, as in Cushing's syndrome, this mechanism for cortisol metabolism may be overwhelmed. As a result, the high levels of co...	{ "Header 1": "Adrenocortical Hormones", "token_count": 2032, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The gene that is transcribed to form the RNA molecule that causes ACTH synthesis initially causes formation of a considerably larger protein, a preprohormone called pro-opiomelanocortin (POMC), which is the precursor of ACTH and several other peptides, including melanocyte-stimulating hormone (MSH), *β-lipotropin, ...	{ "Header 1": "Adrenocortical Hormones", "token_count": 1986, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Leonard Posey.)* This critical need for extra glucocorticoids and the associated severe debility in times of acute stress is called an adrenal (or Addisonian) crisis. #### Hyperadrenalism—Cushing's Syndrome Hypersecretion by the adrenal cortex causes a complex cascade of hormone effects called *Cushing's ...	{ "Header 1": "Adrenocortical Hormones", "token_count": 2029, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Physiol Rev 93:1139, 2013. Dineen R, Stewart PM, Sherlock M: Factors impacting on the action of glucocorticoids in patients receiving glucocorticoid therapy. Clin Endocrinol (Oxf) 90:3, 2019. Feelders RA, Hofland LJ: Medical treatment of Cushing disease. J Clin Endocrinol Metab 98:425, 2013. - Funder JW: Primary ...	{ "Header 1": "Adrenocortical Hormones", "token_count": 811, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The pancreas, in addition to its digestive functions, secretes two major hormones, insulin and glucagon, that are crucial for normal regulation of glucose, lipid, and protein metabolism. Although the pancreas secretes other hormones, such as amylin, somatostatin, and pancreatic polypeptide, their functions are ...	{ "Header 1": "Insulin, Glucagon, and Diabetes Mellitus", "token_count": 2043, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
For example, glucose transporters are moved to the cell membrane to assist glucose entry into the cell. effects on carbohydrate, fat, and protein metabolism. The following are the main end effects of insulin stimulation: - 1. Within seconds after insulin binds with its membrane receptors, the membranes of about 80%...	{ "Header 1": "Insulin, Glucagon, and Diabetes Mellitus", "token_count": 370, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
During much of the day, muscle tissue depends not on glucose but on fatty acids for its energy. The principal reason for this dependence on fatty acids is that the normal resting muscle membrane is only slightly permeable to glucose, except when the muscle fiber is stimulated by insulin; between meals, the amount of ...	{ "Header 1": "Insulin, Glucagon, and Diabetes Mellitus", "Header 2": "Insulin Promotes Muscle Glucose Uptake and Metabolism", "token_count": 2031, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Insulin increases glucose transport into the liver cells. After the liver glycogen concentration reaches 5% to 6%, further glycogen synthesis is inhibited. All the additional glucose entering the liver cells then becomes available to form fat. The glucose is first split to pyruvate in the glycolytic pathway, and the ...	{ "Header 1": "Insulin, Glucagon, and Diabetes Mellitus", "Header 2": "Insulin Promotes Muscle Glucose Uptake and Metabolism", "token_count": 2010, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### Insulin and Growth Hormone Interact Synergistically to Promote Growth Because insulin is required for synthesis of proteins, it is as essential as growth hormone for the growth of an animal. As demonstrated in [Figure 79-6](#page-927-0), a depancreatized, hypophysectomized rat without replacement thera...	{ "Header 1": "Insulin, Glucagon, and Diabetes Mellitus", "Header 2": "Insulin Promotes Muscle Glucose Uptake and Metabolism", "token_count": 2031, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
As discussed later in the chapter, several drugs have been developed to mimic or enhance the actions of incretins for treatment of diabetes mellitus. #### Other Hormones and the Autonomic Nervous System. Other hormones that either directly increase insulin secretion or potentiate the glucose stimulus for insuli...	{ "Header 1": "Insulin, Glucagon, and Diabetes Mellitus", "Header 2": "Insulin Promotes Muscle Glucose Uptake and Metabolism", "token_count": 2005, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Thus, in hypoglycemia, glucagon is secreted in large amounts; it then greatly increases the output of glucose from the liver and thereby serves the important function of correcting the hypoglycemia. Increased Blood Amino Acids Stimulate Secretion of Glucagon. High concentrations of amino acids, such as those that...	{ "Header 1": "Insulin, Glucagon, and Diabetes Mellitus", "Header 2": "Insulin Promotes Muscle Glucose Uptake and Metabolism", "token_count": 2003, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Blood Glucose Concentration Rises to High Levels in Diabetes Mellitus. Lack of insulin decreases the efficiency of peripheral glucose utilization and augments glucose production, raising plasma glucose to 300 to 1200 mg/100 ml. The increased plasma glucose then has multiple adverse effects throughout the body. ...	{ "Header 1": "Insulin, Glucagon, and Diabetes Mellitus", "Header 2": "Insulin Promotes Muscle Glucose Uptake and Metabolism", "token_count": 2035, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### TABLE 79-2 Some Causes of Insulin Resistance - • Obesity/overweight (especially excess visceral adiposity) - • Excess glucocorticoids (Cushing's syndrome or steroid therapy) - • Excess growth hormone (acromegaly) - • Pregnancy, gestational diabetes - • Polycystic ovary disease - • Lipodystrophy (acquired o...	{ "Header 1": "Insulin, Glucagon, and Diabetes Mellitus", "Header 2": "Insulin Promotes Muscle Glucose Uptake and Metabolism", "token_count": 2007, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Glycated Hemoglobin. When blood glucose levels are elevated for prolonged periods of time, glucose attaches to ![](_page_936_Figure_1.jpeg) Figure 79-12. Glucose tolerance curve in a normal person and in a person with diabetes. hemoglobin in red blood cells to form glycated hemoglobin, often called *h...	{ "Header 1": "Insulin, Glucagon, and Diabetes Mellitus", "Header 2": "Insulin Promotes Muscle Glucose Uptake and Metabolism", "token_count": 2021, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Cell 172(1-2):22, 2018. - Mann JP, Savage DB: What lipodystrophies teach us about the metabolic syndrome. J Clin Invest 130:4009, 2019. - Müller TD, Finan B, Clemmensen C, et al: The new biology and pharmacology of glucagon. Physiol Rev 97:721, 2017. - Oram RA, Sims EK, Evans-Molina C: Beta cells in type 1 diabetes: ma...	{ "Header 1": "Insulin, Glucagon, and Diabetes Mellitus", "Header 2": "Insulin Promotes Muscle Glucose Uptake and Metabolism", "token_count": 518, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The physiology of calcium and phosphate metabolism, formation of bone and teeth, and regulation of vitamin D, parathyroid hormone (PTH), and calcitonin are all closely intertwined. The extracellular calcium ion concentration, for example, is determined by the interplay of calcium absorption from the intestine, rena...	{ "Header 1": "Insulin, Glucagon, and Diabetes Mellitus", "Header 2": "Parathyroid Hormone, Calcitonin, Calcium and Phosphate Metabolism, Vitamin D, Bone, and Teeth", "token_count": 1087, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Changing the level of phosphate in the extracellular fluid from far below normal to two to three times normal does not cause major immediate effects on the body. In contrast, even slight increases or decreases of calcium ion in the extracellular fluid can cause extreme immediate physiological effects. In addition, chro...	{ "Header 1": "NONBONE PHYSIOLOGICAL EFFECTS OF ALTERED CALCIUM AND PHOSPHATE CONCENTRATIONS IN THE BODY FLUIDS", "token_count": 577, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Intestinal Absorption and Fecal Excretion of Calcium and Phosphate. The usual rates of intake are approximately 1000 mg/day each for calcium and phosphorus, about the amounts in 1 liter of milk. Normally, divalent cations such as calcium ions are poorly absorbed from the intestines. However, as discussed later, *vitami...	{ "Header 1": "NONBONE PHYSIOLOGICAL EFFECTS OF ALTERED CALCIUM AND PHOSPHATE CONCENTRATIONS IN THE BODY FLUIDS", "Header 2": "ABSORPTION AND EXCRETION OF CALCIUM AND PHOSPHATE", "token_count": 2042, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The collagen monomers polymerize rapidly to form collagen fibers; the resultant tissue becomes osteoid, a cartilage-like material differing from cartilage in that calcium salts readily precipitate in it. As the osteoid is formed, some of the osteoblasts become entrapped in the osteoid and become quiescent. At this st...	{ "Header 1": "NONBONE PHYSIOLOGICAL EFFECTS OF ALTERED CALCIUM AND PHOSPHATE CONCENTRATIONS IN THE BODY FLUIDS", "Header 2": "ABSORPTION AND EXCRETION OF CALCIUM AND PHOSPHATE", "token_count": 2013, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
OPG acts as a "decoy," binding to RANKL and preventing it from interacting with its receptor, thereby inhibiting differentiation of preosteoclasts into mature osteoclasts that resorb bone. OPG opposes the bone resorptive activity of PTH, and mice with a genetic deficiency of OPG have severe decreases in bone mass compa...	{ "Header 1": "NONBONE PHYSIOLOGICAL EFFECTS OF ALTERED CALCIUM AND PHOSPHATE CONCENTRATIONS IN THE BODY FLUIDS", "Header 2": "ABSORPTION AND EXCRETION OF CALCIUM AND PHOSPHATE", "token_count": 2006, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
This latter substance is by far the most active form of vitamin D because the previous products in the scheme of [Figure 80-8](#page-944-1) have less than 1/1000 of the vitamin D effect. Therefore, in the absence of the kidneys, vitamin D loses almost all its effectiveness. Note also in **[Figure 80-8](#page-944-...	{ "Header 1": "NONBONE PHYSIOLOGICAL EFFECTS OF ALTERED CALCIUM AND PHOSPHATE CONCENTRATIONS IN THE BODY FLUIDS", "Header 2": "ABSORPTION AND EXCRETION OF CALCIUM AND PHOSPHATE", "token_count": 2039, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The final hormone has a molecular weight of about 9500. Smaller compounds with as few as 34 amino acids adjacent to the N terminus of the molecule have also been isolated from the parathyroid glands that exhibit full PTH activity. In fact, because the kidneys rapidly remove the whole 84–amino acid hormone within minute...	{ "Header 1": "NONBONE PHYSIOLOGICAL EFFECTS OF ALTERED CALCIUM AND PHOSPHATE CONCENTRATIONS IN THE BODY FLUIDS", "Header 2": "ABSORPTION AND EXCRETION OF CALCIUM AND PHOSPHATE", "token_count": 2025, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
For example, the parathyroid glands become greatly enlarged in persons with rickets, in whom the calcium level is usually depressed only a small amount. These glands also become greatly enlarged during pregnancy, even though the decrease in calcium ion concentration in the mother's extracellular fluid is hardly mea...	{ "Header 1": "NONBONE PHYSIOLOGICAL EFFECTS OF ALTERED CALCIUM AND PHOSPHATE CONCENTRATIONS IN THE BODY FLUIDS", "Header 2": "ABSORPTION AND EXCRETION OF CALCIUM AND PHOSPHATE", "token_count": 2044, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Conversely, a decrease in these concentrations causes immediate absorption of exchangeable salt. This reaction is rapid because the amorphous bone crystals are extremely small and their total surface area exposed to the fluids of the bone is large—perhaps 1 acre or more. In addition, about 5% of all the blood flows t...	{ "Header 1": "NONBONE PHYSIOLOGICAL EFFECTS OF ALTERED CALCIUM AND PHOSPHATE CONCENTRATIONS IN THE BODY FLUIDS", "Header 2": "ABSORPTION AND EXCRETION OF CALCIUM AND PHOSPHATE", "token_count": 2004, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Secondary hyperparathyroidism can be caused by vitamin D deficiency or chronic renal disease in which the damaged kidneys are unable to produce sufficient amounts of the active form of vitamin D, 1,25-dihydroxycholecalciferol. As discussed in more detail in the next section, the vitamin D deficiency leads to *osteoma...	{ "Header 1": "NONBONE PHYSIOLOGICAL EFFECTS OF ALTERED CALCIUM AND PHOSPHATE CONCENTRATIONS IN THE BODY FLUIDS", "Header 2": "ABSORPTION AND EXCRETION OF CALCIUM AND PHOSPHATE", "token_count": 2046, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Many collagen fibers pass directly from the bone of the jaw, through the periodontal membrane, and then into the cementum. These collagen fibers and the cementum hold the tooth in place. When the teeth are exposed to excessive strain, the layer of cementum becomes thicker and stronger. Also, it increases in thickness a...	{ "Header 1": "NONBONE PHYSIOLOGICAL EFFECTS OF ALTERED CALCIUM AND PHOSPHATE CONCENTRATIONS IN THE BODY FLUIDS", "Header 2": "ABSORPTION AND EXCRETION OF CALCIUM AND PHOSPHATE", "token_count": 2023, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### Bibliography Bilezikian JP, Bandeira L, Khan A, Cusano NE: Hyperparathyroidism. Lancet 391:168, 2018. Chande S, Bergwitz C: Role of phosphate sensing in bone and mineral metabolism. Nat Rev Endocrinol 14:637, 2018. Christakos S, Dhawan P, Verstuyf A, et al: Vitamin D: metabolism, molecular mechanism of act...	{ "Header 1": "NONBONE PHYSIOLOGICAL EFFECTS OF ALTERED CALCIUM AND PHOSPHATE CONCENTRATIONS IN THE BODY FLUIDS", "Header 2": "ABSORPTION AND EXCRETION OF CALCIUM AND PHOSPHATE", "token_count": 845, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Male reproductive functions can be divided into three major subdivisions: (1) formation of sperm—spermatogenesis; (2) performance of the male sexual act; and (3) regulation of male reproductive functions by the various hormones. Associated with these reproductive functions are the effects of the male sex hormones on th...	{ "Header 1": "Reproductive and Hormonal Functions of the Male (and Function of the Pineal Gland)", "token_count": 2045, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Luteinizing hormone, secreted by the anterior pituitary gland, stimulates the Leydig cells to secrete testosterone. - 3. Follicle-stimulating hormone, also secreted by the anterior pituitary gland, stimulates the Sertoli cells; without this stimulation, conversion of the spermatids to sperm (the process of spermi...	{ "Header 1": "Reproductive and Hormonal Functions of the Male (and Function of the Pineal Gland)", "token_count": 2032, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Without these changes, the sperm cannot make its way to the interior of the ovum to cause fertilization. #### Acrosome Enzymes, the "Acrosome Reaction," and Penetration of the Ovum Stored in the acrosome of the sperm are large quantities of hyaluronidase and proteolytic enzymes. Hyaluronidase depolymerizes ...	{ "Header 1": "Reproductive and Hormonal Functions of the Male (and Function of the Pineal Gland)", "token_count": 1990, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### Integration of the Male Sexual Act in the Spinal Cord. Although psychic factors usually play an important part in the male sexual act and can initiate or inhibit it, brain function is probably not necessary for its performance ![](_page_963_Picture_2.jpeg) Figure 81-6 Erectile tissue of the penis. ...	{ "Header 1": "Reproductive and Hormonal Functions of the Male (and Function of the Pineal Gland)", "token_count": 1998, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Degradation and Excretion of Testosterone. The testosterone that does not become fixed to the tissues is rapidly converted, mainly by the liver, into androsterone and dehydroepiandrosterone and simultaneously conjugated as either glucuronides or sulfates (glucuronides, particularly). These substances are excr...	{ "Header 1": "Reproductive and Hormonal Functions of the Male (and Function of the Pineal Gland)", "token_count": 1983, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Testosterone has a specific effect on the pelvis to (1) narrow the pelvic outlet, (2) lengthen it, (3) cause a funnel-like shape instead of the broad ovoid shape of the female pelvis, and (4) greatly increase the strength of the entire pelvis for load bearing. In the absence of testosterone, the male pelvis develops ...	{ "Header 1": "Reproductive and Hormonal Functions of the Male (and Function of the Pineal Gland)", "token_count": 2008, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### Regulation of Spermatogenesis by Follicle-Stimulating Hormone and Testosterone FSH binds with specific FSH receptors attached to the Sertoli cells in the seminiferous tubules, which causes the Sertoli cells to grow and secrete various spermatogenic substances. Simultaneously, testosterone (and dihydrotesto...	{ "Header 1": "Reproductive and Hormonal Functions of the Male (and Function of the Pineal Gland)", "token_count": 1999, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### Erectile Dysfunction in the Male Erectile dysfunction, also called "impotence," is characterized by an inability of the man to develop or maintain an erection of sufficient rigidity for satisfactory sexual intercourse. Neurological problems, such as trauma to the parasympathetic nerves from prostate surg...	{ "Header 1": "Reproductive and Hormonal Functions of the Male (and Function of the Pineal Gland)", "token_count": 1743, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Female reproductive functions can be divided into two major phases: (1) preparation of the female body for conception and pregnancy and (2) the period of pregnancy itself. This chapter is concerned with preparation of the female body for pregnancy, and Chapter 83 presents the physiology of pregnancy and childbirth. #...	{ "Header 1": "Female Physiology Before Pregnancy and Female Hormones", "token_count": 2015, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### OVARIAN FOLLICLE GROWTH—THE FOLLICULAR PHASE OF THE OVARIAN CYCLE [Figure 82-5](#page-975-0) shows the progressive stages of follicular growth in the ovaries. When a female child is born, ![](_page_975_Picture_1.jpeg) Figure 82-5. Stages of follicular growth in the ovary, also showing formation...	{ "Header 1": "Female Physiology Before Pregnancy and Female Hormones", "token_count": 2003, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
This process is called luteinization, and the total mass of cells together is called the corpus luteum, which is shown in [Figure 82-5](#page-975-0). A well-developed vascular supply also grows into the corpus luteum. The granulosa cells in the corpus luteum develop extensive intracellular smooth endoplasmi...	{ "Header 1": "Female Physiology Before Pregnancy and Female Hormones", "token_count": 2028, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The theca cells, under the control of luteinizing hormone (LH), produce androgens that diffuse into the granulosa cells. In mature follicles, follicle-stimulating hormone (FSH) acts on granulosa cells to stimulate aromatase activity, which converts the androgens to estrogens. AC, Adenylate cyclase; ATP, adenosine triph...	{ "Header 1": "Female Physiology Before Pregnancy and Female Hormones", "token_count": 507, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
A primary function of the estrogens is to cause cellular proliferation and growth of the tissues of the sex organs and other tissues related to reproduction. Effect of Estrogens on the Uterus and External Female Sex Organs. During childhood, estrogens are secreted only in minute quantities, but at puberty, the quanti...	{ "Header 1": "FUNCTIONS OF THE ESTROGENS—THEIR EFFECTS ON THE PRIMARY AND SECONDARY FEMALE SEX CHARACTERISTICS", "token_count": 2017, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
After menstruation, only a thin layer of endometrial stroma remains, and the only epithelial cells that are left are those located in the remaining deeper portions of the glands and crypts of the endometrium. Under the influence of estrogens, secreted in increasing quantities by the ovary during the first part of the...	{ "Header 1": "FUNCTIONS OF THE ESTROGENS—THEIR EFFECTS ON THE PRIMARY AND SECONDARY FEMALE SEX CHARACTERISTICS", "token_count": 2005, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
#### NEGATIVE FEEDBACK EFFECTS OF ESTROGEN AND PROGESTERONE TO DECREASE LH AND FSH SECRETION Estrogen in small amounts has a strong inhibitory effect on production of LH and FSH. Also, when progesterone is available, the inhibitory effect of estrogen is multiplied, even though progesterone by itself has little ...	{ "Header 1": "FUNCTIONS OF THE ESTROGENS—THEIR EFFECTS ON THE PRIMARY AND SECONDARY FEMALE SEX CHARACTERISTICS", "token_count": 2040, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
In the female, as in the male, the infantile pituitary gland and ovaries are capable of full function if they are appropriately stimulated. However, as is also true in the male, and for reasons that are not understood, the hypothalamus does not secrete significant quantities of GnRH during childhood. Experiments have...	{ "Header 1": "FUNCTIONS OF THE ESTROGENS—THEIR EFFECTS ON THE PRIMARY AND SECONDARY FEMALE SEX CHARACTERISTICS", "token_count": 2014, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Female Orgasm. When local sexual stimulation reaches maximum intensity, and especially when the local sensations are supported by appropriate psychic conditioning signals from the cerebrum, reflexes are initiated that cause the female orgasm, also called the female climax. The female orgasm is analogous to emis...	{ "Header 1": "FUNCTIONS OF THE ESTROGENS—THEIR EFFECTS ON THE PRIMARY AND SECONDARY FEMALE SEX CHARACTERISTICS", "token_count": 2043, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Another common cause of female infertility is salpingitis, that is, inflammation of the fallopian tubes; this inflammation causes fibrosis in the tubes, thereby occluding them. In the past, such inflammation occurred mainly as a result of gonococcal infection. However, with modern therapy, salpingitis is becoming...	{ "Header 1": "FUNCTIONS OF THE ESTROGENS—THEIR EFFECTS ON THE PRIMARY AND SECONDARY FEMALE SEX CHARACTERISTICS", "token_count": 1059, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
In Chapters 81 and 82, the sexual functions of the male and female are described to the point of fertilization of the ovum. If the ovum becomes fertilized, a new sequence of events called gestation or pregnancy takes place, and the fertilized ovum eventually develops into a full-term fetus. The purpose of this chap...	{ "Header 1": "Pregnancy and Lactation", "token_count": 1234, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
After fertilization has occurred, an additional 3 to 5 days is normally required for transport of the fertilized ovum through the remainder of the fallopian tube into the cavity of the uterus (Figure 83-2). This transport is effected mainly by a feeble fluid current in the tube resulting from epithelial secretion p...	{ "Header 1": "Pregnancy and Lactation", "Header 2": "TRANSPORT OF THE FERTILIZED OVUM IN THE FALLOPIAN TUBE", "token_count": 402, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
After reaching the uterus, the developing blastocyst usually remains in the uterine cavity an additional 1 to 3 days before it implants in the endometrium; thus, implantation ordinarily occurs on about the fifth to seventh day after ovulation. Before implantation, the blastocyst obtains its nutrition from the uterine e...	{ "Header 1": "Pregnancy and Lactation", "Header 2": "IMPLANTATION OF THE BLASTOCYST IN THE UTERUS", "token_count": 597, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
While the trophoblastic cords from the blastocyst are attaching to the uterus, blood capillaries grow into the cords from the vascular system of the newly forming embryo. About 21 days after fertilization, blood also ![](_page_992_Figure_10.jpeg) Figure 83-4. Nutrition of the fetus. Most of the early nutrition ...	{ "Header 1": "Pregnancy and Lactation", "Header 2": "ANATOMY AND FUNCTION OF THE PLACENTA", "token_count": 442, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The major function of the placenta is to provide for diffusion of foodstuffs and oxygen from the mother's blood into the fetus's blood and diffusion of excretory products from the fetus back into the mother. In the early months of pregnancy, the placental membrane is still thick because it is not fully developed. The...	{ "Header 1": "Pregnancy and Lactation", "Header 2": "PLACENTAL PERMEABILITY AND MEMBRANE DIFFUSION CONDUCTANCE", "token_count": 2043, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Then, the secretion rate rises rapidly to reach a maximum at about 10 to 12 weeks of pregnancy and decreases back to a lower value by 16 to 20 weeks. It continues at this level for the remainder of the pregnancy. Function of Human Chorionic Gonadotropin. Human chorionic gonadotropin is a glycoprotein having a mol...	{ "Header 1": "Pregnancy and Lactation", "Header 2": "PLACENTAL PERMEABILITY AND MEMBRANE DIFFUSION CONDUCTANCE", "token_count": 2024, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
It is possible that these glucocorticoids help mobilize amino acids from the mother's tissues to be used for synthesis of fetal tissues. Pregnant women usually have about a 2-fold increase in aldosterone secretion, reaching a peak at the end of gestation. This increase, along with the actions of estrogens, causes...	{ "Header 1": "Pregnancy and Lactation", "Header 2": "PLACENTAL PERMEABILITY AND MEMBRANE DIFFUSION CONDUCTANCE", "token_count": 2025, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Second, the renal blood flow and glomerular filtration rate increase up to 50% during normal pregnancy as a result of renal vasodilation. Although the mechanisms that cause renal vasodilation in pregnancy are still unclear, some studies suggest that increased levels of nitric oxide or the ovarian hormone relaxin ma...	{ "Header 1": "Pregnancy and Lactation", "Header 2": "PLACENTAL PERMEABILITY AND MEMBRANE DIFFUSION CONDUCTANCE", "token_count": 2014, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Note especially that twins are born, on average, 19 days earlier than a single child, which emphasizes the importance of mechanical stretch in eliciting uterine contractions. Stretch or Irritation of the Cervix. There is reason to believe that stretching or irritating the uterine cervix is particularly importan...	{ "Header 1": "Pregnancy and Lactation", "Header 2": "PLACENTAL PERMEABILITY AND MEMBRANE DIFFUSION CONDUCTANCE", "token_count": 2026, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
During early involution of the uterus, the placental site on the endometrial surface autolyzes, causing a vaginal discharge known as lochia, which is first bloody and then serous in nature and continues for a total of about 10 days. After this time, the endometrial surface becomes reepithelialized and ready for norma...	{ "Header 1": "Pregnancy and Lactation", "Header 2": "PLACENTAL PERMEABILITY AND MEMBRANE DIFFUSION CONDUCTANCE", "token_count": 1804, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Milk is secreted continuously into the alveoli of the breasts, but it does not flow easily from the alveoli into the ductal system and, therefore, does not continually leak from the nipples. Instead, the milk must be ejected from the alveoli into the ducts before the baby can obtain it. This ejection is caused by a c...	{ "Header 1": "EJECTION (OR \"LET-DOWN\") PROCESS IN MILK SECRETION—FUNCTION OF OXYTOCIN", "token_count": 1912, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
A complete discussion of fetal development, physiology of the child immediately after birth, and growth and development through the early years of life lies within the province of formal courses in obstetrics and pediatrics. However, many physiological principles are peculiar to the infant, and this chapter discusses t...	{ "Header 1": "Fetal and Neonatal Physiology", "token_count": 2031, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
In its absence in laboratory animals, spontaneous abortion usually occurs at an early stage of pregnancy. Vitamin K is used by the fetal liver for formation of Factor VII, prothrombin, and several other blood coagulation factors. When vitamin K is insufficient in the mother, Factor VII and prothrombin become deficien...	{ "Header 1": "Fetal and Neonatal Physiology", "token_count": 2001, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
It is pumped by the right ventricle into the pulmonary artery and then mainly through the ductus arteriosus into the descending aorta, then through the two umbilical arteries into the placenta, where the deoxygenated blood becomes oxygenated. [Figure 84-5](#page-1009-0) shows the relative percentages of the tot...	{ "Header 1": "Fetal and Neonatal Physiology", "token_count": 2006, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
Cardiac Output. The cardiac output of the neonate averages 500 ml/min, which, like respiration and body metabolism, is about twice as much in relation to body weight as in the adult. Occasionally a child is born with an especially low cardiac output caused by hemorrhage of much of its blood volume from the placen...	{ "Header 1": "Fetal and Neonatal Physiology", "token_count": 2040, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
This is particularly true in premature babies because their gastrointestinal tracts absorb calcium even less effectively than do those of normal infants. Need for Iron in the Diet. If the mother has had adequate amounts of iron in her diet, the infant's liver usually has stored enough iron to keep forming blood c...	{ "Header 1": "Fetal and Neonatal Physiology", "token_count": 2035, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The premature infant's temperature tends to approach that of its surroundings. At normal room temperature, the infant's temperature (in degrees Fahrenheit) may stabilize in the low 90s or even in the 80s. Studies show that a body temperature maintained below 96°F (35.5°C) is associated with a particularly high incidenc...	{ "Header 1": "Fetal and Neonatal Physiology", "token_count": 1779, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
There are few stresses to which the body is exposed that approach the extreme stresses of heavy exercise. In fact, if some of the extremes of exercise were continued for even moderately prolonged periods, they might be lethal. Therefore, sports physiology is mainly a discussion of the ultimate limits to which several o...	{ "Header 1": "Sports Physiology", "token_count": 1969, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }
The amounts stored are approximately the following: \| \| g/kg Muscle \| \|------------------------\|-------------\| \| High-carbohydrate diet \| 40 \| \| Mixed diet \| 20 \| \| High-fat diet \| 6 \| #### Muscle Metabolic Systems in Exercise The same ba...	{ "Header 1": "Sports Physiology", "token_count": 2009, "source_pdf": "datasets/websources/biochem/1671268744mpp.pdf" }