Chapter 7.PDF

Exam Name___________________________________ MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Which of the following is NOT a method of hormone action? 1) A) control of electrical signa...

Exam Name___________________________________ MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Which of the following is NOT a method of hormone action? 1) A) control of electrical signaling pathways B) control of ion or molecule transport across cell membranes C) control of enzymatic reaction rates D) control of gene expression and protein synthesis E) All are methods of hormone action. Answer: E Section Title: The Classification of Hormones Learning Outcome: 7.1 2) When a catecholamine or peptide hormone binds to receptors on the surface of a cell, 2) A) the cell becomes inactive. B) the hormone is transported to the nucleus where it alters the activity of DNA. C) the cell membrane becomes less permeable. D) a second messenger appears in the cytoplasm. E) None of the answers are correct. Answer: D Section Title: The Classification of Hormones Learning Outcome: 7.1 3) The link between a first messenger and a second messenger in a cell that responds to peptide 3) hormones is usually A) cGMP. B) cAMP. C) calcium. D) adenylyl cyclase. E) a G protein. Answer: E Section Title: The Classification of Hormones Learning Outcome: 7.1 4) When adenylyl cyclase is activated, 4) A) protein kinases are metabolized. B) steroids are produced. C) cAMP is formed. D) calcium ions are released from intracellular stores. E) cAMP is broken down. Answer: C Section Title: The Classification of Hormones Learning Outcome: 7.1 1 5) Typically, when steroid hormones bind to their receptors, 5) A) adenylyl cyclase is activated. B) protein kinases are activated. C) G proteins are inhibited. D) cyclic nucleotides are formed. E) gene transcription may increase or decrease. Answer: E Section Title: The Classification of Hormones Learning Outcome: 7.1 6) Steroid hormones are synthesized in the ________ of the cell. 6) A) mitochondria B) smooth endoplasmic reticulum C) Golgi apparatus D) rough endoplasmic reticulum E) nucleus Answer: B Section Title: The Classification of Hormones Learning Outcome: 7.1 7) Each of the following statements concerning peptide hormones is true except one. Identify the 7) exception. A) Prohormones can be activated before their release via post-translational modification. B) Peptide hormones remain in circulation for relatively short periods of time. C) Peptide hormones in the bloodstream are always bound to carrier proteins. D) Peptide hormones are first synthesized as prohormones. E) Peptide hormones interact with receptors on the surface of their target cells. Answer: C Section Title: The Classification of Hormones Learning Outcome: 7.2 8) Each of the following hormones is an amino acid derivative except one. Identify the exception. 8) A) thyroid hormone B) norepinephrine C) thyroid-stimulating hormone D) epinephrine E) melatonin Answer: C Section Title: The Classification of Hormones Learning Outcome: 7.1 9) The majority of hormones in the body are 9) A) steroid hormones. B) amino acid-derived hormones. C) peptide hormones. D) neurohormones. E) All of the hormones are present in equal amounts in the body. Answer: C Section Title: The Classification of Hormones Learning Outcome: 7.1 2 10) The most complex endocrine responses involve the 10) A) thyroid gland. B) thymus. C) pancreas. D) adrenal glands. E) hypothalamus. Answer: E Section Title: Control of Hormone Release Learning Outcome: 7.2 11) The posterior pituitary gland secretes 11) A) TSH. B) MSH. C) FSH. D) ADH (Vasopressin). E) ACTH. Answer: D Section Title: Control of Hormone Release Learning Outcome: 7.3 12) The pituitary hormone that controls the release of glucocorticoids from the adrenal cortex is 12) A) LH. B) TSH. C) ACTH. D) FSH. E) STH. Answer: C Section Title: Control of Hormone Release Learning Outcome: 7.3 13) The pituitary hormone that controls hormone synthesis and release from the thyroid gland is 13) A) STH. B) TSH. C) LH. D) FSH. E) ACTH. Answer: B Section Title: Control of Hormone Release Learning Outcome: 7.3 14) The pituitary hormone that stimulates milk production by the mammary glands is 14) A) FSH. B) growth hormone. C) TSH. D) prolactin. E) ACTH. Answer: D Section Title: Control of Hormone Release Learning Outcome: 7.3 15) The pituitary hormone that stimulates cell growth and metabolism in many tissues is 15) A) MSH. B) ACTH. C) insulin. D) prolactin. E) somatotropin. Answer: E Section Title: Control of Hormone Release Learning Outcome: 7.3 3 SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. Match each term with the appropriate description. A. peptide hormone B. steroid hormone C. amino acid-derived hormone D. anterior pituitary E. hypothalamus F. posterior pituitary 16) lipophobic molecule that interacts with receptors on cell surface 16) Answer: A Section Title: Control of Hormone Release Learning Outcome: 7.2 17) site of vasopressin synthesis 17) Answer: E Section Title: Control of Hormone Release Learning Outcome: 7.1 18) true endocrine gland of epithelial origin 18) Answer: D Section Title: Control of Hormone Release Learning Outcome: 7.3 19) cannot be stored in secretory vesicles 19) Answer: B Section Title: Control of Hormone Release Learning Outcome: 7.1 20) derivatives of tyrosine 20) Answer: C Section Title: Control of Hormone Release Learning Outcome: 7.1 21) storage and release site for oxytocin 21) Answer: F Section Title: Control of Hormone Release Learning Outcome: 7.1 4 Match each hormone with its primary source. A. prolactin B. insulin C. aldosterone D. melatonin E. calcitonin F. epinephrine 22) adrenal medulla 22) Answer: F Section Title: Control of Hormone Release Learning Outcome: 7.1 23) pancreas 23) Answer: B Section Title: Control of Hormone Release Learning Outcome: 7.1 24) thyroid 24) Answer: E Section Title: Control of Hormone Release Learning Outcome: 7.1 25) anterior pituitary 25) Answer: A Section Title: Control of Hormone Release Learning Outcome: 7.1 26) adrenal cortex 26) Answer: C Section Title: Control of Hormone Release Learning Outcome: 7.1 27) pineal 27) Answer: D Section Title: Control of Hormone Release Learning Outcome: 7.1 28) The study of hormones is known as the field of ________. 28) Answer: endocrinology Section Title: Hormones Learning Outcome: 7.1 29) The ________ of a hormone is an indicator of how long a hormone is active in the body. 29) Answer: half-life Section Title: The Classification of Hormones Learning Outcome: 7.1 5 30) A circulatory route that has two sets of capillaries is known as a ________. 30) Answer: portal system Section Title: Control of Hormone Release Learning Outcome: 7.3 31) The posterior pituitary gland is also known as the ________. 31) Answer: neurohypophysis Section Title: Control of Hormone Release Learning Outcome: 7.3 32) The anterior pituitary gland is also known as the ________. 32) Answer: adenophyophysis Section Title: Control of Hormone Release Learning Outcome: 7.3 33) The sex hormones that regulate the male and female reproductive organs are collectively 33) called ________. Answer: gonadotropins Section Title: Control of Hormone Release Learning Outcome: 7.1 34) ________ is a decrease in the number of receptors of target cells in order to dampen the 34) effects of excess hormone. Answer: Down-regulation Section Title: Endocrine Pathologies Learning Outcome: 7.7 35) The ________ gland sits along the superior border of the kidney. 35) Answer: adrenal Section Title: The Classification of Hormones Learning Outcome: 7.1 36) The outer layer of the adrenal gland is called the ________. 36) Answer: adrenal cortex Section Title: The Classification of Hormones Learning Outcome: 7.1 37) The inner portion of the adrenal gland is called the ________. 37) Answer: adrenal medulla Section Title: The Classification of Hormones Learning Outcome: 7.1 38) The adrenal cortex produces a steroid hormone called ________ that controls Na+ and K+ 38) homeostasis and another steroid hormone called ________ that controls blood glucose levels. Answer: aldosterone, cortisol Section Title: The Classification of Hormones Learning Outcome: 7.1 6 39) The term for two hormones that have additive effects is ________. 39) Answer: synergists Section Title: Hormone Interaction Learning Outcome: 7.7 40) The term that describes the need for one hormone to be present for a second hormone to 40) produce a full effect is called ________. Answer: permissive Section Title: Hormone Interaction Learning Outcome: 7.7 41) Two hormones that have opposing effects are called ________. 41) Answer: antagonists Section Title: Hormone Interaction Learning Outcome: 7.7 42) When an organ or gland shrinks due to lack of use, that condition is referred to as 42) ________. Answer: atrophy Section Title: Endocrine Pathologies Learning Outcome: 7.8 43) The term for any hormone that controls the secretion of another hormone is a ________. 43) Answer: trophic hormone Section Title: Control of Hormone Release Learning Outcome: 7.4 44) The hormones of the anterior pituitary are controlled by trophic hormones from the 44) ________. Answer: hypothalamus Section Title: Control of Hormone Release Learning Outcome: 7.4 45) The trophic hormones reach the pituitary through the ________. 45) Answer: hypothalamic-hypophyseal portal system Section Title: Control of Hormone Release Learning Outcome: 7.4 46) ________ pathologies arise in the last endocrine gland in a reflex. 46) Answer: Primary Section Title: Endocrine Pathologies Learning Outcome: 7.8 47) A ________ is a problem with one of the tissues producing trophic hormones. 47) Answer: secondary pathology Section Title: Endocrine Pathologies Learning Outcome: 7.8 7  48) Chemical signals released into the blood by neurons are called ________. 48) Answer: neurohormones Section Title: Control of Hormone Release Learning Outcome: 7.1 MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 49) When stimulated by a particular hormone, there is a marked increase in the activity of G proteins in 49) the membrane. The hormone is probably A) aldosterone. B) testosterone. C) a steroid. D) a peptide. E) estrogen. Answer: C Section Title: The Classification of Hormones Learning Outcome: 7.2 50) After a hormone has exerted its effects, it typically 50) A) is inactivated or removed from the blood. B) is absorbed by the gland that secreted it. C) is absorbed by its target cell. D) continues to act until an opposing hormone is secreted. E) spontaneously degrades. Answer: A Section Title: Hormones Learning Outcome: 7.1 51) Hormones are not typically considered to be cytokines because hormones are ________ like 51) cytokines. A) not effective in small amounts B) secreted into the blood, not C) not peptides D) synthesized in advance and stored, not E) secreted by cells, not Answer: D Section Title: Hormones Learning Outcome: 7.1 52) In a simple endocrine reflex, the endocrine cell is the 52) A) sensor only. B) target. C) integrating center and target. D) sensor and integrating center. E) integrating center only. Answer: D Section Title: Control of Hormone Release Learning Outcome: 7.5 8  53) Synergism occurs when 53) A) one hormone triggers the secretion of a second hormone. B) one hormone inhibits the release of a second hormone. C) a hormone can exert its full effects only in the presence of another hormone. D) hormones working together produce a larger effect than predicted. E) hormones working together produce a smaller effect than predicted. Answer: D Section Title: Hormone Interaction Learning Outcome: 7.7 54) Hormones acting through signal transduction pathways elicit a ________ response compared to 54) hormones that produce genomic effects. A) faster B) equal C) slower Answer: A Section Title: Endocrine Pathologies Learning Outcome: 7.1 SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. 55) A cell's or tissue's response to a hormone primarily depends on ________ and ________. 55) Answer: cell receptors, signal transduction pathways Section Title: Hormones Learning Outcome: 7.7 56) The signal molecule produced by one animal that may affect the behavior of another 56) animal of the same species is the ________. Answer: pheromone or ectohormone Section Title: Hormones Learning Outcome: 7.1 57) A signal molecule that is secreted into the external environment, instead of into the blood, 57) is called a(n) ________. Answer: ectohormone or pheromone Section Title: Hormone Learning Outcome: 7.1 ESSAY. Write your answer in the space provided or on a separate sheet of paper. 58) Describe the classic steps for identifying an endocrine gland. Are these steps practical for identifying the sources of all the hormones we know of today? Explain. Answer: 1. Remove the suspected gland, and observe the animal. 2. Restore the gland or administer a gland extract, and observe the animal. 3. Add a gland or gland extract to a normal animal, and observe the animal for excessive response. 4. Purify gland extracts and isolate the substance. There are many hormones that are secreted from cells that are not part of a discrete gland and therefore not removable without causing problems beyond loss of the hormone. Section Title: Hormone Learning Outcome: 7.2 9 59) List and explain two ways hormones affect their targets. Answer: Second messenger systems activated by peptide hormones modify existing proteins or activate gene transcription to synthesize new proteins. Steroid hormones activate gene transcription to synthesize new proteins, and like peptide hormones, some steroids have nongenomic responses. Section Title: The Classification of Hormones Learning Outcome: 7.1 60) List the three types of hormone interactions and provide an example of each. Answer: Synergism, permissiveness, and antagonism. An example of synergism is epinephrine's ability to potentiate the effects of glucagon in elevating blood glucose levels. Reproductive hormones along with adequate thyroid hormone have a permissive effect on the reproductive system because both are required for normal development. Glucagon and insulin are antagonistic hormones because they have opposing physiological actions on blood glucose levels. Section Title: Hormone Interactions Learning Outcome: 7.7 61) Explain the differences among the terms paracrine, autocrine, hormone, and cytokine. Answer: Discussed in Chapters 6 and 7. Hormones are chemical messengers that are traditionally defined as being secreted by specialized cells into the blood and transported via the circulatory system to distant cells and tissues. Paracrine and autocrine chemical messengers diffuse only very short distances through interstitial fluid. Cytokines may act both at local and long-distance targets. Section Title: Hormone Learning Outcome: 7.1 62) What are two benefits of having a portal system that connects the hypothalamus with the anterior pituitary gland? Are there any other endocrine axes connected by a portal system? Answer: One benefit of a portal system is that it ensures that the controlling hormones will be delivered directly to the target cells. Secondly, since the hormones go directly to their target cells without first passing through the general circulation they are not diluted. The hypothalamus can control the cells of the pituitary with much smaller amounts of releasing and inhibiting hormones than would be necessary if the hormones had to first go through the circulatory pathway before reaching the pituitary. This is the only endocrine portal system. Section Title: Control of Hormone Release Learning Outcome: 7.3 63) A given hormone generally has the same effect on different target tissues. Is this statement TRUE or FALSE? Defend your answer. Answer: False. A target tissue's response is dependent upon the exact receptor involved, as well as a variety of other factors. For example, insulin causes skeletal muscle to increase its rate of transport of glucose into the cell, but in the liver insulin affects the activity of enzymes not directly related to glucose transport. Section Title: Hormones Learning Outcome: 7.1 64) What normally stops hormone action, and why is this important? Answer: Hormones are degraded by enzymes and eliminated in the urine. This disposal of hormones is essential to the ability to regulate their action and prevent them from being too effective. For example, if insulin were not closely regulated, too much glucose could be removed from the blood, depriving brain cells of their only fuel source and causing brain damage, coma, and/or death. Section Title: Hormones Learning Outcome: 7.1 10 65) How does the embryological origin of the two distinct parts of the pituitary gland relate to the control of secretion and the types of hormones produced? Answer: The posterior pituitary is an extension of the brain, specifically of the hypothalamus. This part of the pituitary secretes hormones that are synthesized in the hypothalamus, in response to signals from the hypothalamus. The hormones secreted are neurohormones. The anterior pituitary is an outgrowth from the roof of the mouth that fuses to the posterior pituitary during fetal development. This part of the pituitary is true glandular epithelium, and the secretion of its hormones is regulated by releasing and inhibiting hormones secreted by the hypothalamus. In either case, then, the types of hormones and the regulation of their secretion is predictable based on the type of tissue involved. Section Title: Control of Hormone Release Learning Outcome: 7.3 66) Explain the concept of evolutionary conservation of hormone activity, and how recognition of that phenomenon has influenced hormone therapies. Answer: Hormone structure and function in some cases have changed little from primitive vertebrates through mammals. Evidence for this includes the similar response in humans to injected hormones from nonhuman sources. An example of the importance of this relationship is provided by the hormone insulin, which, from extracts of cow, pig, or sheep pancreas, successfully treated diabetes mellitus in humans. Prior to that, diagnosis of diabetes mellitus was followed shortly by death. Section Title: Hormone Evolution Learning Outcome: 7.8 67) One hypothalamic hormone triggers a pituitary hormone to cause release of an adrenal hormone. Fill in the names of the hormones below. If a tumor in the adrenal cortex resulted in hypercortisolism, how would this affect the relative levels of hormone produced from each source? What type of reflex pathway is involved? Hormone Source Tumor effects ________________________ Hypothalamus increase decrease ________________________ Anterior pituitary increase decrease ________________________ Adrenal cortex increase decrease Answer: Corticotropin-releasing hormone, decrease Adrenocorticotrophic hormone, decrease Cortisol, increase This type of relationship is called long-loop negative feedback. Section Title: Endocrine Pathologies Learning Outcome: 7.8 68) Dexamethasone is a drug used to suppress the secretion of ACTH from the anterior pituitary gland. Two patients with hypersecretion of cortisol are given dexamethasone. Anika's cortisol secretion level falls to normal after the medication, but Bonnie's cortisol secretion remains elevated. Which patient has primary hypercortisolism, also known as Cushing's syndrome? Explain your reasoning. Answer: Dexamethasone suppresses the pituitary's activity, the secretion of ACTH, which then allowed Anika's level to decline. Since Bonnie's level did not decline, this shows that the hypersecretion is NOT due to ACTH, thus it must be coming from the adrenal gland. This is the definition of a primary hypersecretion an elevated amount from the last gland in the reflex pathway. Section Title: Endocrine Pathologies Learning Outcome: 7.8 11 69) The following statement contains three parts that are either TRUE or FALSE. You must address ALL THREE parts of the statement explaining either why it is TRUE or why it is FALSE. Neurohormones from the anterior pituitary are called "trophic" because their release is stimulated by a releasing hormone from the hypothalamus. Answer: 1. The anterior pituitary is an endocrine gland; it does not release neurohormones because its cells are not neurons. 2. The word trophic is used incorrectly; the term refers to a hormone that causes another gland to release hormone. 3. Anterior pituitary hormones are in fact triggered by releasing hormones from the hypothalamus. Section Title: Control of Hormone Release Learning Outcome: 7.4 70) Carl is suffering from hypothyroidism. What is hypothyroidism? How could his physician determine whether the malfunction is in the hypothalamus and pituitary or at the level of the gland itself? Answer: Hypothyroidism results when the thyroid gland produces lower than normal amounts of thyroid hormones. The physician could order blood tests to determine the levels of T3 , T4, and TSH in the blood. If the condition is due to disease of the thyroid gland, you would expect to see elevated levels of TSH because of a lack of feedback inhibition by thyroid hormones. If, on the other hand, the problem is due to problems at the level of the hypothalamus or pituitary, you would expect to see decreased levels of TSH. Section Title: Endocrine Pathologies Learning Outcome: 7.8 71) Candace is a normal-looking 15-year-old girl but has never had a menstrual period, though she has other signs of puberty such as breasts and pubic and axillary hair. During a pelvic exam her physician determines that she has no uterus. Blood tests reveal that she has elevated amounts of testosterone in her blood, similar to that expected in young adult males. Name two typical sources of testosterone. Given the lack of a uterus, what is the likely source of testosterone in this case? What may be wrong with her? (Hint: Consider general principles of hormone secretion and action.) Why is there no uterus? What genetic test may confirm this suspicion? Answer: Testosterone is produced by adrenal glands and testes. The presence of elevated testosterone combined with absence of a uterus suggests that she has testes rather than ovaries. The lack of masculinization indicates that her tissues do not respond to the testosterone that is present. There is no uterus because she is genetically male. This can be confirmed by examining her chromosomes. Such individuals have "androgen insensitivity syndrome." Section Title: Endocrine Pathologies Learning Outcome: 7.8 72) Your roommate Sally has just found out her mother has high cholesterol. Knowing that health problems often run in families, Sally has decided to eliminate cholesterol from her diet. Her goal is to have no cholesterol in her body. She has asked you for advice on achieving this goal. Is her goal realistic? Explain. What information should you give her to help her establish a more realistic goal? Assuming she could banish cholesterol from her body, what would be the endocrine consequences? Answer: Her goal is not realistic. If Sally avoids eating animal products, she can easily eliminate cholesterol from her diet. She cannot, however, eliminate cholesterol from her blood because it is produced by her own liver. Furthermore, such a goal is incompatible with life, as cholesterol is a structural component of cell membranes. Cholesterol is also the precursor to the steroid hormones, which are essential for normal health. Section Title: The Classification of Hormones Learning Outcome: 7.8 12 73) Thyroid hormone secretion decreases with age. Treatment with thyroid-releasing hormone is less effective in younger patients, while treatment with thyroid hormone is more effective in younger patients. What name is given to the condition of decreased thyroid hormone secretion? What related hormones are likely to decrease as well? Propose an explanation for the loss of responsiveness to the releasing hormone. Propose an explanation for the increased responsiveness to treatment with thyroid hormone (consider both how hormones affect target cells and how hormone action is halted). Answer: The condition is hypothyroidism. Thyroid-stimulating hormone and thyroid-releasing hormone likely also decrease. Decreased responsiveness to injected releasing hormone may indicate a loss of hormone receptors in the anterior pituitary. Increased responsiveness to injected thyroid hormone may indicate up-regulation of hormone receptors in the target tissues, or it may indicate decreased metabolism of the circulating hormone. Section Title: Endocrine Pathologies Learning Outcome: 7.8 74) There are two forms of diabetes: diabetes mellitus (lack of insulin regulation of cellular uptake of glucose) and diabetes insipidus (lack of regulation of water loss in the urine by the hormone antidiuretic hormone or ADH). In each case, there are two similar explanations for the resulting pathology. What are they? (Hint: Consider general principles of hormone action.) Answer: Diabetes mellitus can result from lack of insulin secretion or from lack of response of insulin receptors. Diabetes insipidus can result from lack of ADH secretion or lack of responsiveness of ADH receptors. Section Title: Endocrine Pathologies Learning Outcome: 7.8 75) Assume the following: The total area of cell membrane in a single fat cell is 104 mm2 , there is one insulin receptor per 1 mm2 of membrane, and 1 mm2 of cell membrane contains 106 phospholipid molecules. 1. How many insulin receptors are in a fat cell? 2. How many phospholipids molecules are in a fat cell? 3. How many phospholipid molecules are there for each insulin receptor? 4. What general principle of hormone action does your answer support? Answer: 1. 1 receptor/1 mm2 × 104 mm2 /cell = 104 receptors per cell. 2. 104 mm2/cell × 106 phospholipids/mm2 = 1010 phospholipid molecules per cell. 3. (1010 phospholipids/cell) / (104 receptors/cell) = 106 phospholipid molecules per insulin receptor. 4. Hormones exert their effects at very low concentrations (therefore it is not surprising that the hormone receptors, through which the hormones act, are also in low concentration). Section Title: Hormones Learning Outcome: N/A 13 76) Suzie wants to protect virgin forests from destruction. She climbs a tree to prevent loggers from cutting the oldest tree in the forest. Suzie did not eat for twelve hours until a friend, Jammie, took over the vigilance. Match the correct levels of blood glucose concentration, blood insulin concentration and relative membrane insulin receptor concentration for a skeletal muscle cell 20 hours into Jammie's fast and one hour after Suzie had eaten a peanut butter and banana sandwich and a bowl of sweet potato soup. Plasma Glucose: 90 mg/dl; 125 mg/dl Plasma Insulin: 10iuU/ml (70 pmol/L); 40iuU/ml (280 pmol/L) Relative membrane insulin receptor concentration: increasing (high); decreasing (low) Fasting (Jammie) Satiety (Suzie) Plasma Glucose Plasma Insulin Relative Membrane Insulin Receptor Levels Answer: Fasting (Jammie) Satiety (Suzie) Plasma Glucose 90 mg/dl 125 mg/dl Plasma Insulin 10iuU/ml (70 pmol/L); 40iuU/ml (280 pmol/L) Relative Membrane increasing (high) decreasing (low) Insulin Receptor Levels Section Title: Control of Hormone Release Learning Outcome: 7.5 14