EXAM 5 UNIT 15
109. Which of the following would most likely occur in the earliest stages of type II diabetes? A) Increased insulin sensitivity B) High circulating levels of C-peptide C) Decreased hepatic glucose output D) Metabolic acidosis E) Hypovolemia
B) High circulating levels of C-peptide
116. A man suffers from a disease that destroyed only the motor neurons of the spinal cord below the thoracic region. Which aspect of sexual function would not be possible? A) Arousal B) Erection C) Lubrication D) Ejaculation
D) Ejaculation
83. Which of the following is produced by the trophoblast cells during the first 3 weeks of pregnancy? A) Estrogen B) Luteinizing hormone C) Oxytocin D) Human chorionic gonadotropin E) None of the above
D) Human chorionic gonadotropin
106. Which of the following findings is most likely to occur in a patient who has uncontrolled type 1 diabetes mellitus? A) Decreased plasma osmolality B) Increased plasma volume C) Increased plasma pH D) Increased release of glucose from the liver E) Decreased rate of lipolysis
D) Increased release of glucose from the liver
30. Which of the following is most likely to produce the greatest increase in insulin secretion? A) Amino acids B) Amino acids and glucose C) Amino acids and somatostatin D) Glucose and somatostatin
B) Amino acids and glucose
34. As menstruation ends estrogen levels in the blood rise rapidly. What is the source of the estrogen? A) Corpus luteum B) Developing follicles C) Endometrium D) Stromal cells of the ovaries E) Anterior pituitary gland
B) Developing follicles
129. Which blood vessel in the fetus has the highest Po2? A) Ductus arteriosus B) Ductus venosus C) Ascending aorta D) Left atrium
B) Ductus venosus
141. Which of the following increases the rate of deposition and decreases the rate of absorption of bone? A) Elevation of parathyroid hormone concentration B) Elevation of estrogen concentration C) Elevation of extracellular hydrogen ion concentration D) Reduction in mechanical stress on the bone
B) Elevation of estrogen concentration
105. A patient comes to the emergency room and is found to have a slightly below-normal concentration of calcium in the blood (calcium ion activity = 0.9 mmol/L), a phosphate concentration approximately 50% below normal (HPO4 − = 0.5 mmol/L), and undetectable amounts of calcium ion in the urine. Which of the following would one expect to find in this patient? A) Above normal calcitonin concentration in the blood B) Greater than normal parathyroid hormone concentration in the blood C) Suppressed osteoclastic activity in the bone D) Below normal blood pH
B) Greater than normal parathyroid hormone concentration in the blood
112. A scientist studying developmental physiology performs an experiment in which a substance is given to pregnant rats that give birth to pups that have XY chromosomes but female genital organs. What was the substance given to the rats? A) An antibody that blocked the effect of human chorionic gonadotropin in the embryo and fetus B) A large quantity of estrogen-like compounds C) Follicle-stimulating hormone D) Testosterone
A) An antibody that blocked the effect of human chorionic gonadotropin in the embryo and fetus
123. Failure of the ductus arteriosus to close is a common developmental defect. Which of the following would likely be present in a 12-month-old infant with patent ductus arteriosus? A) Below-normal arterial PO2 B) Below-normal arterial PCO2 C) Greater than normal arterial blood pressure D) Lower than normal pulmonary arterial pressure
A) Below-normal arterial PO2
18. When do progesterone levels rise to their highest point during the female hormonal cycle? A) Between ovulation and the beginning of menstruation B) Immediately before ovulation C) When the blood concentration of luteinizing hormone is at its highest point D) When 12 primary follicles are developing to the antral stage
A) Between ovulation and the beginning of menstruation
13. Exposure to UV light directly facilitates which of the following? A) Conversion of cholesterol to 25-hydroxycholicalciferol B) Conversion of 25-hydroxycholicalciferol to 1,25-dihydroxycholicalciferol C) Transport of calcium into the extracellular fluid D) Formation of calcium binding protein E) Storage of vitamin D3 in the liver
A) Conversion of cholesterol to 25-hydroxycholicalciferol
8. In the figure, line D most likely illustrates the influence of which of the following? A) Exercise B) Obesity C) Growth hormone D) Cortisol E) Glucagon
A) Exercise
51. Delayed breathing at birth is a common danger faced by newborn infants. What is a frequent cause of delayed breathing? A) Fetal hypoxia during the birth process B) Maternal hypoxia during the birth process C) Fetal hypercapnia D) Maternal hypercapnia
A) Fetal hypoxia during the birth process
126. Why is osteoporosis much more common in elderly women than in elderly men? A) Men continue to produce testosterone throughout their lifetime, whereas women cease estrogen production after menopause B) Women consume less dietary calcium than men C) Gastrointestinal absorption of calcium is more effective in men than in women D) The bones of women contain less calcium than those of men even before menopause
A) Men continue to produce testosterone throughout their lifetime, whereas women cease estrogen production after menopause
146. A man who has been exposed to high levels of gamma radiation is sterile due to destruction of the germinal epithelium of the seminiferous tubules, although he has normal levels of testosterone. Which of the following would be found in this patient? A) Normal secretory pattern of gonadotropin-releasing hormone B) Normal levels of inhibin C) Suppressed levels of follicle-stimulating hormone D) Absence of Leydig cells
A) Normal secretory pattern of gonadotropin-releasing hormone
127. When compared with the late-evening values typically observed in normal subjects, plasma levels of both adrenocorticotropic hormone and cortisol would be expected to be higher in which of the following individuals? A) Normal subjects after waking in the morning B) Normal subjects administered dexamethasone C) Patients with Cushing's syndrome (adrenal adenoma) D) Patients with Addison's disease E) Patients with Conn's syndrome
A) Normal subjects after waking in the morning
98. The function of which of the following is increased by an elevated parathyroid hormone concentration? A) Osteoclasts B) Hepatic formation of 25-hydroxycholecalciferol C) Phosphate reabsorptive pathways in the renal tubules D) All of the above
A) Osteoclasts
47. Giving prostaglandin E2 (PGE2) to a pregnant woman may result in an abortion. What is the best explanation for this finding? A) PGE2 strongly stimulates uterine contraction B) PGE2 causes constriction of the arteries leading to the placenta C) PGE2 stimulates the release of oxytocin from the posterior pituitary D) PGE2 increases the secretion of progesterone from the corpus luteum
A) PGE2 strongly stimulates uterine contraction
119. Birth control pills containing combinations of synthetic estrogen and progesterone compounds given for the first 21 days of the menstrual cycle are effective in preventing pregnancy. What is the explanation for their efficacy? A) Prevention of the preovulatory surge of luteinizing hormone secretion from the pituitary gland B) Prevention of development of the ovarian follicles C) Suppressing function of the corpus luteum soon after it forms D) Prevention of normal development of the endometrium
A) Prevention of the preovulatory surge of luteinizing hormone secretion from the pituitary gland
48. During the first few years after menopause, follicle-stimulating hormone (FSH) levels are normally extremely high. A 56-year-old woman completed menopause 3 years ago. However, she is found to have low levels of FSH in her blood. Which of the following is the best explanation for this finding? A) She has been receiving hormone replacement therapy with estrogen and progesterone since she completed menopause B) Her adrenal glands continue to produce estrogen C) Her ovaries continue to secrete estrogen D) She took birth control pills for 20 years before menopause
A) She has been receiving hormone replacement therapy with estrogen and progesterone since she completed menopause
89. If a woman hears her baby cry, she may experience milk ejection from the nipples even before the baby is placed to the breast. What is the explanation for this? A) The sound of the hungry baby's cry elicits secretion of oxytocin from the posterior pituitary, which reaches the breast and causes contraction of the myoepithelial cells B) The sound of the hungry baby's cry causes a reflex relaxation of the myoepithelial cells, allowing the milk to flow C) The sound of the hungry baby's cry elicits a surge of prolactin from the anterior pituitary, which promptly stimulates milk production from the breast D) The sound of the hungry baby's cry elicits sympathetic nervous system discharge that causes contraction of the myoepithelial cells
A) The sound of the hungry baby's cry elicits secretion of oxytocin from the posterior pituitary, which reaches the breast and causes contraction of the myoepithelial cells
138. Which of the following metabolic responses would be expected during the postabsorptive period, compared to the postprandial state? Glucagon Secretion Hormone Sensitive Lipase Adipocyte a Glycerol Phsophate
A. Glucagon Secretion INC Hormone Sensitive Lipase INC Adipocyte a Glycerol Phsophate DEC
54. Why is milk produced only after delivery, not before? A) Levels of luteinizing hormone and follicle-stimulating hormone are too low during pregnancy to support milk production B) High levels of progesterone and estrogen during pregnancy suppress milk production C) The alveolar cells of the breast do not reach maturity until after delivery D) High levels of oxytocin are required for milk production to begin, and oxytocin is not secreted until the baby stimulates the nipple
B) High levels of progesterone and estrogen during pregnancy suppress milk production
31. In order for male differentiation to occur during embryonic development, testosterone must be secreted from the testes. What stimulates the secretion of testosterone during embryonic development? A) Luteinizing hormone from the maternal pituitary gland B) Human chorionic gonadotropin C) Inhibin from the corpus luteum D) Gonadotropin-releasing hormone from the embryo's hypothalamus
B) Human chorionic gonadotropin
16. Spermatogenesis is regulated by a negative feedback control system in which follicle-stimulating hormone (FSH) stimulates the steps in sperm cell formation. What is the negative feedback signal associated with sperm cell production that inhibits pituitary formation of FSH? A) Testosterone B) Inhibin C) Estrogen D) Luteinizing hormone
B) Inhibin
71. RU486 causes abortion if it is administered before or soon after implantation. What is the specific effect of RU486? A) It binds to luteinizing hormone receptors, stimulating the secretion of progesterone from the corpus luteum B) It blocks progesterone receptors so that progesterone has no effect within the body C) It blocks the secretion of follicle-stimulating hormone by the pituitary D) It blocks the effects of oxytocin receptors in the uterine muscle
B) It blocks progesterone receptors so that progesterone has no effect within the body
117. A sustained program of lifting heavy weights will increase bone mass. What is the mechanism of this effect of weightlifting? A) Elevated metabolic activity stimulates parathyroid hormone secretion B) Mechanical stress on the bones increases the activity of osteoblasts C) Elevated metabolic activity results in an increase in dietary calcium intake D) Elevated metabolic activity results in stimulation of calcitonin secretion
B) Mechanical stress on the bones increases the activity of osteoblasts
39. Which of the following decreases the resistance in the arteries leading to the sinuses of the penis? A) Stimulation of the sympathetic nerves innervating the arteries B) Nitric oxide C) Inhibition of activity of the parasympathetic nerves leading to the arteries D) All of the above
B) Nitric oxide
96. Men who take large doses of testosterone-like androgenic steroids for long periods are sterile in the reproductive sense of the word. What is the explanation for this finding? A) High levels of androgens bind to testosterone receptors in the Sertoli cells, resulting in overstimulation of inhibin formation B) Overstimulation of sperm cell production results in the formation of defective sperm cells C) High levels of androgen compounds inhibit the secretion of gonadotropin-releasing hormone by the hypothalamus, resulting in the inhibition of luteinizing hormone and follicle-stimulating hormone release by the anterior pituitary D) High levels of androgen compounds produce hypertrophic dysfunction of the prostate gland
B) Overstimulation of sperm cell production results in the formation of defective sperm cells
75. During pregnancy, the uterine smooth muscle is quiescent. During the 9th month of gestation the uterine muscle becomes progressively more excitable. What factors contribute to the increase in excitability? A) Placental estrogen synthesis rises to high rates B) Progesterone synthesis by the placenta decreases C) Uterine blood flow reaches its highest rate D) Prostaglandin E2 synthesis by the placenta decreases E) Activity of the fetus falls to low levels
B) Progesterone synthesis by the placenta decreases
94. Before intercourse, a woman irrigates her vagina with a solution that lowers the pH of the vaginal fluid to 4.5. What will be the effect on sperm cells in the vagina? A) Metabolic rate will increase B) Rate of movement will decrease C) Formation of prostaglandin E2 will increase D) Rate of oxygen consumption will increase
B) Rate of movement will decrease
23. In the circulatory system of a fetus, which of the following is greater before birth than after birth? A) Arterial Po2 B) Right atrial pressure C) Aortic pressure D) Left ventricular pressure
B) Right atrial pressure
64. Very early in embryonic development, testosterone is formed within the male embryo. What is the function of this hormone at this stage of development? A) Stimulation of bone growth B) Stimulation of development of male sex organs C) Stimulation of development of skeletal muscle D) Inhibition of luteinizing hormone secretion
B) Stimulation of development of male sex organs
102. Infants of mothers who had adequate nutrition during pregnancy do not require iron supplements or a diet rich in iron until about 3 months of age. Why is this? A) Growth of the infant does not require iron until after the 3rd month B) The fetal liver stores enough iron to meet the infant's needs until the third month C) Synthesis of new red blood cells begins after 3 months D) Muscle cells that develop before the 3rd month do not contain myoglobin
B) The fetal liver stores enough iron to meet the infant's needs until the third month
10. A baby is born with a penis, a scrotum with no testes, no vagina, and XX chromosomes. This condition is referred to as hermaphroditism. Which of the following could cause this abnormality? A) Abnormally high levels of human chorionic gonadotropin production by the trophoblast cells B) The presence of a testosterone-secreting tumor in the mother's right adrenal gland C) Abnormally high levels of luteinizing hormone in the maternal blood D) Abnormally low levels of testosterone in the maternal blood E) Abnormally low rates of estrogen production by the placenta
B) The presence of a testosterone-secreting tumor in the mother's right adrenal gland
148. Hormone 1 is which of the following? A) Thyroid-releasing hormone B) Thyroid-stimulating hormone (TSH) C) Thyroxine (T4) D) Adrenocorticotropic hormone (ACTH) E) Cortisol
B) Thyroid-stimulating hormone (TSH)
63. When compared with resting conditions, which of the previous sets of metabolic changes would most likely occur during exercise? Hepatic Gluclose Uptake Muscle Glucose Uptake Hormone-sensitive Lipase Activity
B. Hepatic Gluclose Uptake INC Muscle Glucose Uptake DEC Hormone-sensitive Lipase Activity INC
61. In a normal young man, what is the maximum pressure that can be achieved within the corpora cavernosa during a sexual experience? A) 20 to 40 mm Hg B) 60 to 80 mm Hg C) 150 to 250 mm Hg D) 400 to 600 mm Hg
C) 150 to 250 mm Hg
12. Which of the following could inhibit the initiating labor? A) Administration of an antagonist of the actions of progesterone B) Administration of luteinizing hormone C) Administration of an antagonist of prostaglandin E2 effects D) Mechanically dilating and stimulating the cervix E) Administration of oxytocin
C) Administration of an antagonist of prostaglandin E2 effects
The red lines in the figure above illustrate the normal relationships between plasma insulin concentration and glucose production in the liver and between plasma insulin concentration and glucose uptake in muscle. 6. In the figure, which lines most likely illustrate these relationships in a patient with type 2 diabetes? A) A and C B) A and D C) B and C D) B and D term-0
C) B and C
The red lines in the figure above illustrate the normal relationships between plasma insulin concentration and glucose production in the liver and between plasma insulin concentration and glucose uptake in muscle. 7. In the figure, which lines most likely illustrate these relationships in a patient with acromegaly? A) A and C B) A and D C) B and C D) B and D
C) B and C
149. Hormone 2 is which of the following? A) TSH B) T4 C) Corticotropin-releasing hormone D) ACTH E) Cortisol
C) Corticotropin-releasing hormone
56. Which of the following increases the rate of excretion of calcium ions by the kidney? A) Decrease in calcitonin concentration in the plasma B) Increase in phosphate ion concentration in the plasma C) Decrease in the plasma level of parathyroid hormone D) Metabolic alkalosis
C) Decrease in the plasma level of parathyroid hormone
78. Before the preovulatory surge in luteinizing hormone, granulosa cells of the follicle secrete which of the following? A) Testosterone B) Progesterone C) Estrogen D) Inhibin
C) Estrogen
143. What is the most common cause of respiratory distress syndrome in neonates born at 7 months gestation? A) Pulmonary edema due to pulmonary arterial hypertension B) Formation of a hyaline membrane over the alveolar surface C) Failure of the alveolar lining to form adequate amounts of surfactant D) Excessive permeability of the alveolar membrane to water
C) Failure of the alveolar lining to form adequate amounts of surfactant
41. A 40-year-old woman comes to the emergency room with a fracture in the neck of the femur. Radiographs reveal generalized demineralization of the bone in the area. Her plasma calcium ion concentration is significantly greater than normal: 12.2 mg/dL. Which of the following conditions is consistent with this presentation? A) Osteoporosis B) Rickets C) Hyperparathyroidism D) Renal failure
C) Hyperparathyroidism
73. Which of the following decreases the rate of urinary excretion of calcium ions by the kidney? A) Increase in calcitonin concentration in the plasma B) Decrease in phosphate ion concentration in the plasma C) Increase in the plasma level of parathyroid hormone D) Metabolic acidosis E) Increase in calcium ion activity in the plasma
C) Increase in the plasma level of parathyroid hormone
5. Within minutes following a normal delivery, flow through the foramen ovale decreases dramatically. What is the cause of this change? A) Increased formation of prostaglandin E2 in the endocardium B) Increased rate of flow through the pulmonary artery C) Increased left atrial pressure D) Increased right atrial pressure E) Increased Po2
C) Increased left atrial pressure
67. A 30-year-old woman is breast-feeding her infant. During suckling, which of the following hormonal responses is expected? A) Increased secretion of antidiuretic hormone (ADH) from the supraoptic nuclei B) Increased secretion of ADH from the paraventricular nuclei C) Increased secretion of oxytocin from the paraventricular nuclei D) Decreased secretion of neurophysin E) Increased plasma levels of both oxytocin and ADH
C) Increased secretion of oxytocin from the paraventricular nuclei
21. Estrogen is required for normal reproductive function in the male. Where is the principal site of estrogen synthesis in the male? A) Leydig cells B) Osteoblasts C) Liver cells D) Prostate cells
C) Liver cells
85. At birth, a large, well-nourished baby is found to have a plasma glucose concentration of 17 mg/dL (normal is 80 to 100 mg/dL) and a plasma insulin concentration twice the normal value. What is the explanation for these findings? A) Neonate suffered from in utero malnutrition B) Mother was malnourished during pregnancy C) Mother is diabetic, with poorly controlled hyperglycemia D) Mother is obese
C) Mother is diabetic, with poorly controlled hyperglycemia
92. A neonate develops a jaundice condition with a bilirubin concentration of 10 mg/dL on day 2 (normal is 3 mg/dL at 2 days old). The neonatologist can be confident that the condition is not erythroblastosis fetalis if which of the following is true? A) Bilirubin concentration rises no further B) Hematocrit falls only slightly C) Mother, father, and neonate are all Rh-negative D) Mother has no history of hepatic dysfunction
C) Mother, father, and neonate are all Rh-negative
122. In order for milk to flow from the nipple of the mother into the mouth of the nursing infant, which of the following must occur? A) Myoepithelial cells must relax B) Prolactin levels must fall C) Oxytocin secretion from the posterior pituitary must take place D) The baby's mouth must develop a strong negative pressure over the nipple E) All of the above
C) Oxytocin secretion from the posterior pituitary must take place
137. During the week following ovulation, the endometrium increases in thickness to 5 to 6 millimeters. What stimulates this increase in thickness? A) Luteinizing hormone B) Estrogen from the corpus luteum C) Progesterone from the corpus luteum D) Follicle-stimulating hormone
C) Progesterone from the corpus luteum
145. A 45-year-old woman has a mass in the sella turcica that compresses the portal vessels, disrupting pituitary access to hypothalamic secretions. The secretion rate of which of the following hormones would most likely increase in this patient? A) Adrenocorticotropic hormone B) Growth hormone C) Prolactin D) Luteinizing hormone E) Thyroid-stimulating hormone
C) Prolactin
72. Following ejaculation, arterial blood flow into the corpora cavernosa decreases back to the normal resting level resulting in the flaccid state. What is the best explanation for this decrease in blood flow? A) Systemic arterial pressure decreases due to absence of sexual stimulation B) The level of sympathetic stimulation to the arterioles supplying the corpora cavernosa decreases C) Resistance of the arterioles supplying the corpora cavernosa increases D) Formation of nitric oxide in the endothelial cells of the arterioles supplying the corpora cavernosa is stimulated by the increase in parasympathetic nervous system activity E) Resistance of the venules draining the sinuses of the corpora cavernosa increases
C) Resistance of the arterioles supplying the corpora cavernosa increases
125. The placenta does which of the following? A) Develops from the granulosa cells B) Secretes luteinizing hormone C) Secretes estrogen D) Allows direct mixing of maternal and fetal blood E) None of the above
C) Secretes estrogen
121. A "birth control" compound for men has been sought for several decades. Which of the following would provide effective sterility? A) Substance that mimics the actions of luteinizing hormone B) Substance that blocks the actions of inhibin C) Substance that blocks the actions of follicle-stimulating hormone D) Substance that mimics the actions of gonadotropin-releasing hormone
C) Substance that blocks the actions of follicle-stimulating hormone
69. Why is it important to feed newborn infants every few hours? A) The hepatic capacity to store and synthesize glycogen and glucose is not adequate to maintain the plasma glucose concentration in a normal range for more than a few hours after feeding B) If adequate fluid is not ingested frequently, the plasma protein concentration will rise to greater than normal levels within a few hours C) The function of the gastrointestinal system is poorly developed and can be improved by keeping food in the stomach at all times D) The hepatic capacity to form plasma proteins is minimal and requires the constant availability of amino acids from food to avoid hypoproteinemic edema
C) The function of the gastrointestinal system is poorly developed and can be improved by keeping food in the stomach at all times
81. Neonates that are kept in 100% oxygen incubators for several days become blind when they are removed from the incubator, a condition referred to as retrolental fibroplasia. What is the explanation for the loss of sight? A) The high concentration of oxygen stimulates the growth of fibrous tissue into the retina B) The high concentration of oxygen causes rupture of blood vessels in the retina, resulting in fibrous infiltration of the vitreous humor C) The high concentration of oxygen retards the growth of blood vessels in the retina, but when the oxygen therapy is stopped, the fall in oxygen concentration stimulates an overgrowth of blood vessels in the retina and vitreous humor, which later become densely fibrous and block the light from the pupil D) The high concentration of oxygen destroys the retinal neurons
C) The high concentration of oxygen retards the growth of blood vessels in the retina, but when the oxygen therapy is stopped, the fall in oxygen concentration stimulates an overgrowth of blood vessels in the retina and vitreous humor, which later become densely fibrous and block the light from the pupil
66. A patient arrives in the emergency room apparently in cardiogenic shock due to a massive heart attack. His initial arterial blood sample reveals the following concentrations of ions: Sodium 137 mmol/L Bicarbonate 14 mmol/L Free calcium 2.8 mmol/L Potassium 4.8 mmol/L pH 7.16 To correct the acidosis, the attending physician begins an infusion of sodium bicarbonate and after 1 hr takes another blood sample, which reveals the following values: Sodium 138 mmol/L Bicarbonate 22 mmol/L Free calcium 2.3 mmol/L Potassium 4.5 mmol/L pH 7.34 What is the cause of the decrease in calcium ion concentration? A) The increase in arterial pH resulting from the sodium bicarbonate infusion inhibited parathyroid hormone secretion B) The increase in pH resulted in the stimulation of osteoblasts, which removed calcium from the circulation C) The increase in pH resulted in an elevation in the concentration of HPO4−, which shifted the equilibrium between HPO4− and Ca++toward CaHPO4 D) The increase in arterial pH stimulated the formation of 1,25-dihydroxycholecalciferol, which resulted in an increased rate of absorption of calcium from the gastrointestinal tract
C) The increase in pH resulted in an elevation in the concentration of HPO4−, which shifted the equilibrium between HPO4− and Ca++toward CaHPO4
53. A 3-week-old infant is brought to the emergency room in a comatose condition. The history reveals that her parents have been feeding her concentrated, undiluted formula for 5 days. (Infant formula preparations are often sold in concentrated forms that must be properly diluted with water before feeding.) The infant's plasma osmolality is 352 mOsm/L (normal is 280 to 300 mOsm/L), and the osmolality of the urine is 497 mOsm/L. What is the explanation for the hyperosmotic condition of the plasma? A) The infant has inappropriate antidiuretic hormone regulation B) The infant has excessive secretion of aldosterone C) The infant is unable to form urine sufficiently concentrated to excrete the solute load from the formula without losing more water than required to maintain normal plasma osmolality D) The infant has a renal collecting duct abnormality that prevents it from forming concentrated urine
C) The infant is unable to form urine sufficiently concentrated to excrete the solute load from the formula without losing more water than required to maintain normal plasma osmolality
134. During the latter stages of pregnancy, many women experience an increase in body hair growth in a masculine pattern. What is the explanation for this? A) The ovaries secrete some testosterone along with the large amounts of estrogen produced late in pregnancy B) The fetal ovaries and testes secrete androgenic steroids C) The maternal and fetal adrenal glands secrete large amounts of androgenic steroids that are used by the placenta to form estrogen D) The placenta secretes large amounts of estrogen, some of which is metabolized to testosterone
C) The maternal and fetal adrenal glands secrete large amounts of androgenic steroids that are used by the placenta to form estrogen
135. What is the cause of menopause? A) Reduced levels of gonadotropic hormones secreted from the anterior pituitary gland B) Reduced responsiveness of the follicles to the stimulatory effects of gonadotropic hormones C) Reduced rate of secretion of progesterone from the corpus luteum D) Reduced numbers of follicles available in the ovary for stimulation by gonadotropic hormones
D) Reduced numbers of follicles available in the ovary for stimulation by gonadotropic hormones
80. Based on the figure above, which set of curves most likely reflects the responses in a healthy individual and in a patient in the early stages of Cushing's syndrome? Healthy Cushing's syndrome A) 3 2 B) 1 2 C) 1 3 D) 2 1 E) 2 3
D) 2 1
110. A baby is born with a penis, a scrotum with no testes, no vagina, and XX chromosomes. This condition is referred to as hermaphroditism. Which of the following could cause this abnormality? A) Abnormally high levels of human chorionic gonadotropin production by the trophoblast cells B) Abnormally low rates of estrogen production by the placenta C) Abnormally high levels of luteinizing hormone in the maternal blood D) Abnormally high levels of testosterone in the maternal blood
D) Abnormally high levels of testosterone in the maternal blood
132. Extracellular calcium concentration remains only slightly below normal for many months even when dietary calcium intake is minimal. What accounts for this ability to maintain calcium concentration in the extracellular fluid? A) Only a slight reduction in plasma calcium concentration stimulates large, sustained increases in parathyroid hormone secretion B) Osteoclasts stimulated by high levels of parathyroid hormone remove calcium from the large quantity stored in the bone, thereby maintaining the near-normal extracellular calcium level C) Renal excretion of calcium is greatly reduced under the influence of high concentrations of parathyroid hormone D) All of the above
D) All of the above
33. Extracellular ionic calcium activity will be decreased within 1 min by which of the following? A) Increase in extracellular phosphate ion activity B) Increase in extracellular pH C) Decrease in extracellular Pco2 D) All of the above E) None of the above
D) All of the above
104. Where does fertilization normally take place? A) Uterus B) Cervix C) Ovary D) Ampulla of the fallopian tubes
D) Ampulla of the fallopian tubes
9. One treatment for erectile dysfunction requires the injection of a substance into the corpora cavernosa of the penis. The injection of which of the following causes an erection? A) Norepinephrine B) A substance that inhibits formation of nitric oxide C) Thromboxane A2, which is a vasoconstrictor prostaglandin D) Angiotensin II E) None of the above
D) Angiotensin II
28. Which of the following is greater after birth than before birth? A) Flow through the foramen ovale B) Pressure in the right atrium C) Flow through the ductus arteriosus D) Aortic pressure
D) Aortic pressure
1. Seven days after ovulation, pituitary secretion of luteinizing hormone (LH) decreases rapidly. What is the cause of this decrease in secretion? A) The anterior pituitary gland becomes unresponsive to the stimulatory effect of gonadotropinreleasing hormone (GnRH) B) Estrogen from the developing follicles exerts a feedback inhibition on the hypothalamus C) The rise in body temperature inhibits hypothalamic release of GnRH D) Secretion of estrogen and progesterone by the corpus luteum suppresses hypothalamic secretion of GnRH and pituitary secretion of LH E) None of the above
D) Secretion of estrogen and progesterone by the corpus luteum suppresses hypothalamic secretion of GnRH and pituitary secretion of LH
108. Two days before the onset of menstruation, secretions of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) reach their lowest levels. What is the cause of this low level of secretion? A) The anterior pituitary gland becomes unresponsive to the stimulatory effect of gonadotropinreleasing hormone (GnRH) B) Estrogen from the developing follicles exerts a feedback inhibition on the hypothalamus C) The rise in body temperature inhibits hypothalamic release of GnRH D) Secretion of estrogen, progesterone, and inhibin by the corpus luteum suppresses hypothalamic secretion of GnRH and pituitary secretion of FSH
D) Secretion of estrogen, progesterone, and inhibin by the corpus luteum suppresses hypothalamic secretion of GnRH and pituitary secretion of FSH
42. A man eats a low carbohydrate meal rich in proteins containing the amino acids that stimulate insulin secretion. Which of the following responses accounts for the absence of hypoglycemia? A) Suppression of growth hormone B) Suppression of somatomedin C secretion C) Stimulation of cortisol secretion D) Stimulation of glucagon secretion E) Stimulation of epinephrine secretion
D) Stimulation of glucagon secretion
37. A female athlete who took testosterone-like steroids for several months stopped having normal menstrual cycles. What is the best explanation for this observation? A) Testosterone stimulates inhibin production from the corpus luteum B) Testosterone binds to receptors in the endometrium, resulting in the endometrium's failure to develop during the normal cycle C) Testosterone binds to receptors in the anterior pituitary that stimulate the secretion of folliclestimulating hormone (FSH) and luteinizing hormone (LH) D) Testosterone inhibits the hypothalamic secretion of gonadotropin-releasing hormone and the pituitary secretion of LH and FSH
D) Testosterone inhibits the hypothalamic secretion of gonadotropin-releasing hormone and the pituitary secretion of LH and FSH
140. Before implantation, the blastocyst obtains its nutrition from the uterine endometrial secretions. How does the blastocyst obtain nutrition during the first week after implantation? A) It continues to derive nutrition from endometrial secretions B) The cells of the blastocyst contain stored nutrients that are metabolized for nutritional support C) The placenta provides nutrition derived from maternal blood D) The trophoblast cells digest the nutrient-rich endometrial cells and then absorb their contents for use by the blastocyst
D) The trophoblast cells digest the nutrient-rich endometrial cells and then absorb their contents for use by the blastocyst
29. Parathyroid hormone directly A) controls the rate of 25-hydroxycholicalciferol formation B) controls the rate of calcium transport in the mucosa of the small intestine C) controls the rate of formation of calcium binding protein D) controls the rate of formation of 1, 25-dihydroxycholicalciferol E) stimulates renal tubular phosphate reabsorption
D) controls the rate of formation of 1, 25-dihydroxycholicalciferol
62. When compared with the postabsorptive state, which of the previous sets of metabolic changes would most likely occur during the postprandial state? Hepatic Gluclose Uptake Muscle Glucose Uptake Hormone-sensitive Lipase Activity
D. Hepatic Gluclose Uptake INC Muscle Glucose Uptake INC Hormone-sensitive Lipase Activity DEC
79. Based on the following figure, which set of curves most likely reflects the responses in a healthy individual and in patients with type 1 and type 2 diabetes mellitus (DM)?
E
45. A man is taking a number of medications, one of which appears to be interfering with the emission phase of the sexual act. Which of the following medications could cause this problem? A) A medication that prolongs the duration of action of nitric oxide B) A medication that blocks the smooth muscle receptors for nitric oxide C) A medication that increases the release of nitric oxide D) A testosterone-like androgen compound E) An inhibitor of beta-adrenergic nervous system receptors
E) An inhibitor of beta-adrenergic nervous system receptors
11. A young woman is given daily injections of a substance beginning on the 16th day of her normal menstrual cycle and continuing for 3 weeks. As long as the injections continue, she does not menstruate. The injected substance could be which of the following? A) Testosterone B) FSH C) An inhibitor of progesterone's actions D) A prostaglandin E2 inhibitor E) HCG
E) HCG
86. Which of the following stimulates the secretion of parathyroid hormone (PTH)? A) Increase in extracellular calcium ion activity above the normal value B) Increase in calcitonin concentration C) Respiratory acidosis D) Increased secretion of PTH-releasing hormone from the hypothalamus E) None of the above
E) None of the above
22. A professional athlete in her mid-20s has not had a menstrual cycle for 5 years, although a bone density scan revealed normal skeletal mineralization. Which of the following facts elicited during the taking of her medical history may explain these observations? A) She consumes a high-carbohydrate diet B) Her grandmother suffered a hip fracture at age 79 C) Her blood pressure is greater than normal D) Her plasma estrogen concentration is very low E) She has been taking anabolic steroid supplements for 5 years
E) She has been taking anabolic steroid supplements for 5 years
124. Which of the following sets of physiological changes would be expected in a non-diabetic patient with Cushing's disease? plasma aldosterone plasma cortisol plasma insulin
F. plasma aldosterone SAME plasma cortisol INC plasma insulin INC
