endocrine and reproductive system Flashcards by Moustafa Ahmed Abdul Aziz

Which receptor controls nitric oxide (NO) release to
cause vasodilation during penile erection?
A) Leptin receptor
B) Angiotensin AT1 receptor
C) Endothelin ETA receptor
D) Muscarinic receptor

D) Muscarinic receptor

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Which statement about antidiuretic hormone (ADH)
is true?
A) It is synthesized in the posterior pituitary gland
B) It increases salt and water reabsorption in the collecting tubules and ducts
C) It stimulates thirst
D) It has opposite effects on urine and plasma osmolality

D) It has opposite effects on urine and plasma osmolality

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After menopause, hormone replacement therapy with
estrogen-like compounds is effective in preventing the
progression of osteoporosis. What is the mechanism of
their protective effect?
A) They stimulate the activity of osteoblasts
B) They increase absorption of calcium from the gastrointestinal tract
C) They stimulate calcium reabsorption by the renal
tubules
D) They stimulate parathyroid hormone (PTH) secretion by the parathyroid glan

A) They stimulate the activity of osteoblasts

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A patient has nephrogenic diabetes insipidus. Of the
following options, which outcome would be expected
or which intervention would be suggested?
A) Expected outcome: decreased plasma sodium concentration
B) Expected outcome: increased secretion of ADH
from the supraoptic and paraventricular nuclei
C) Expected outcome: high urine osmolality
D) Suggested intervention: water restriction
E) Suggested intervention: ADH antagonists (vaptans)

B) Expected outcome: increased secretion of ADH

from the supraoptic and paraventricular nuclei

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Within minutes after a normal delivery, flow through
the foramen ovale decreases dramatically. What is the
cause of this change?
A) Increased formation of prostaglandin E2 (PGE2) in
the endocardium
B) Increased rate of flow through the pulmonary
artery
C) Increased left atrial pressure
D) Increased right atrial pressure
E) Increased partial pressure of oxygen (Po2)

C) Increased left atrial pressure

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Which hormones antagonize the effect of NO and cause the penis to become flaccid after orgasm?
A) Endothelin and norepinephrine
B) Estrogen and progesterone
C) Luteinizing hormone (LH) and follicle-stimulating
hormone (FSH)
D) Progesterone and LH

A) Endothelin and norepinephrine

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10. Thecal cells in the follicle are not able to produce what 
sex steroid?
A) Estradiol
B) Testosterone
C) Progesterone
D) Dihydrotestosterone

A) Estradiol

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A baby is born with a penis, a scrotum with no testes,
no vagina, and XX chromosomes. This condition is referred to as hermaphroditism. What could cause this
abnormality?
A) Abnormally high levels of human chorionic gonadotropin (HCG) 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 LH 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

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A young woman is given daily injections of a substance
beginning on the sixteenth 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 PGE2 inhibitor
E) HCG

E) HCG

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13. Which of the following increases secretion of GH?
A) Senescence
B) Insulin-like growth factor-1 (IGF-1)
C) Somatostatin
D) Hypoglycemia
E) Exogenous GH administration

D) Hypoglycemia

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Which of the following could inhibit the initiation of
labor?
A) Administration of an antagonist of the actions of
progesterone
B) Administration of LH
C) Administration of an antagonist of PGE2 effects
D) Mechanically dilating and stimulating the cervix
E) Administration of oxytocin

C) Administration of an antagonist of PGE2 effects

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Exposure to ultraviolet 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

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Which of the following decreases the pressure in the
pulmonary artery after birth?
A) An increase in systemic arterial pressure
B) Closure of ductus arteriosus
C) An increase in left ventricular pressure
D) A decrease in pulmonary vascular resistance

D) A decrease in pulmonary vascular resistance

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17. Which of the following is both synthesized and stored 
in the hypothalamus?
A) ADH
B) Thyroid-stimulating hormone (TSH)
C) LH
D) Somatostatin
E) Somatomedin

D) Somatostatin

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If a radioimmunoassay is properly conducted and the
amount of radioactive hormone bound to antibody is
low, what would this result indicate?
A) Plasma levels of endogenous hormone are high
B) Plasma levels of endogenous hormone are low
C) More antibody is needed
D) Less radioactive hormone is needed

A) Plasma levels of endogenous hormone are high

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By which mechanism do LH and FSH return to baseline levels?
A) LH surge
B) Negative feedback on gonadotropin-releasing hormone (GnRH) by progesterone
C) Negative feedback on GnRH by estradiol
D) Negative feedback on GnRH from testosterone

C) Negative feedback on GnRH by estradiol

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Spermatogenesis is regulated by a negative feedback
control system in which FSH stimulates the steps in
sperm cell formation. Which negative feedback signal
associated with sperm cell production inhibits pituitary formation of FSH?
A) Testosterone
B) Inhibin
C) Estrogen
D) LH

B) Inhibin

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Which of the following is true during the 12-hour
period preceding ovulation?
A) A surge of LH is secreted from the pituitary
B) The surge occurs immediately after the formation
of the corpus luteum
C) The surge is followed immediately by a fall in the
plasma concentration of progesterone
D) The number of developing follicles is increasing

B) The surge occurs immediately after the formation

of the corpus luteum

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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 LH is at its highest point
D) When 12 primary follicles are developing to the antral stag

A) Between ovulation and the beginning of menstruation

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What accompanies sloughing of the endometrium during the endometrial cycle in a normal woman?
A) An increase in progesterone
B) The LH “surge”
C) A decrease in both progesterone and estrogen
D) An increase in estradiol

C) A decrease in both progesterone and estrogen

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Some cells secrete chemicals into the extracellular fluid
that act on cells in the same tissue. Which of the following refers to this type of regulation?
A) Neural
B) Endocrine
C) Neuroendocrine
D) Paracrine
E) Autocrine

D) Paracrine

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Which of the following pairs is an example of the type
of regulation referred to in Question 24?
A) Somatostatin—GH secretion
B) Somatostatin—insulin secretion
C) Dopamine—prolactin secretion
D) Norepinephrine—corticotropin-releasing hormone
(CRH) secretion
E) CRH—adrenocorticotropic hormone (ACTH)
secretion

B) Somatostatin—insulin secretion

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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
fact may explain these observations?
A) She consumes a high-carbohydrate diet
B) Her grandmother sustained a hip fracture at age
79 years
C) Her blood pressure is higher 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

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27. What is the nongenomic effect of testosterone on vascular smooth muscle?
A) Vasodilation
B) Vasoconstriction
C) Increase in prostaglandins
D) Increase in estrogen receptors

A) Vasodilation

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``` 28. 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

``` 32. Which enzyme in the cytochrome P450 steroid synthesis cascade is directly responsible for estradiol synthesis? A) 17-beta-hydroxysteroid dehydrogenase B) 5-alpha reductase C) Aromatase D) Side chain cleavage enzyme ```

C) Aromatase

``` 33. 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

34. PTH does what 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

``` 35. Which substances are 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

37. 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) LH from the maternal pituitary gland B) HCG C) Inhibin from the corpus luteum D) GnRH from the embryo’s hypothalamus

B) HCG

38. A patient has an elevated plasma thyroxine (T4) concentration, a low plasma TSH concentration, and her thyroid gland is smaller than normal. What is the most likely explanation for these findings? A) A lesion in the anterior pituitary that prevents TSH secretion B) The patient is taking propylthiouracil C) The patient is taking thyroid extract D) The patient is consuming large amounts of iodine E) Graves’ disease

C) The patient is taking thyroid extract

39. Extracellular ionic calcium activity will be decreased within 1 minute by which of the following? A) An increase in extracellular phosphate ion activity B) An increase in extracellular pH C) A decrease in extracellular partial pressure of carbon dioxide (Pco2) D) All the above E) None of the above

D) All the above

40. 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

41. A 30-year-old woman reports to the clinic for a routine physical examination. The examination reveals she is pregnant. Her plasma levels of TSH are high, but her total thyroid hormone concentration is normal. Which of the following best reflects the patient’s clinical state? A) Graves’ disease B) Hashimoto’s disease C) A pituitary tumor secreting TSH D) A hypothalamic tumor secreting thyrotropinreleasing hormone (TRH) E) The patient is taking thyroid extract

B) Hashimoto’s disease

42. Which anterior pituitary hormone plays a major role in the regulation of a nonendocrine target gland? A) ACTH B) TSH C) Prolactin D) FSH E) LH

C) Prolactin

43. 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 failure of the endometrium to develop during the normal cycle C) Testosterone binds to receptors in the anterior pituitary that stimulate the secretion of FSH and LH D) Testosterone inhibits the hypothalamic secretion of GnRH and the pituitary secretion of LH and FSH

D) Testosterone inhibits the hypothalamic secretion of | GnRH and the pituitary secretion of LH and FSH

45. 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) NO C) Inhibition of activity of the parasympathetic nerves leading to the arteries D) All the above

B) NO

46. A patient has a goiter associated with high plasma levels of both TRH and TSH. Her heart rate is elevated. This patient most likely has which condition? A) An endemic goiter B) A hypothalamic tumor secreting large amounts of TRH C) A pituitary tumor secreting large amounts of TSH D) Graves’ disease

B) A hypothalamic tumor secreting large amounts of | TRH

47. A man eats a low-carbohydrate meal that is rich in proteins containing the amino acids that stimulate insulin secretion. Which response accounts for the absence of hypoglycemia? A) Suppression of GH 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

48. A 46-year-old man has “puffy” skin and is lethargic. His plasma TSH concentration is low and increases markedly when he is given TRH. What is the most likely diagnosis? A) Hyperthyroidism due to a thyroid tumor B) Hyperthyroidism due to an abnormality in the hypothalamus C) Hypothyroidism due to an abnormality in the thyroid D) Hypothyroidism due to an abnormality in the hypothalamus E) Hypothyroidism due to an abnormality in the pituitary

D) Hypothyroidism due to an abnormality in the | hypothalamus

49. Negative feedback on FSH release from the anterior pituitary in men that results in a reduction in estradiol production is due to which hormone? A) Progesterone B) Estradiol C) Testosterone D) Inhibin

D) Inhibin

50. During the first few years after menopause, 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. What 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

``` 51. Blockade of what receptors will prolong erection in the male? A) Estrogen receptors B) Cholesterol receptors C) Muscarinic receptors D) Phosphodiesterase-5 receptors ```

D) Phosphodiesterase-5 receptors

52. Which of the following pairs of hormones and the corresponding action is incorrect? A) Glucagon—increased glycogenolysis in liver B) Glucagon—increased glycogenolysis in skeletal muscle C) Glucagon—increased gluconeogenesis D) Cortisol—increased gluconeogenesis E) Cortisol—decreased glucose uptake in muscle

B) Glucagon—increased glycogenolysis in skeletal | muscle

54. What is a frequent cause of delayed breathing at birth? 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

``` 55. Which hormone is largely unbound to plasma proteins? A) Cortisol B) T4 C) ADH D) Estradiol E) Progesterone ```

C) ADH

56. What is the mechanism by which the zona pellucida becomes “hardened” after penetration of a sperm cell to prevent a second sperm from penetrating? A) A reduction in estradiol B) The proteins released from the acrosome of the sperm C) An increase in intracellular calcium in the oocyte D) An increase in testosterone that affects the sperm

C) An increase in intracellular calcium in the oocyte

57. Why is milk produced by a woman only after delivery, not before? A) Levels of LH and FSH 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

58. Which of the following increases the rate of excretion of calcium ions by the kidney? A) A decrease in calcitonin concentration in the plasma B) An increase in phosphate ion concentration in the plasma C) A decrease in the plasma level of PTH D) Metabolic alkalosis

C) A decrease in the plasma level of PTH

61. If a woman has a tumor that is secreting large amounts of estrogen from the adrenal gland, which of the following will occur? A) Progesterone levels in the blood will be very low B) Her LH secretion rate will be totally suppressed C) She will not have normal menstrual cycles D) Her bones will be normally calcified E) All the above

E) All the above

63. 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 LH secretion

B) Stimulation of development of male sex organs

64. Which change would be expected to occur with increased binding of a hormone to plasma proteins? A) Increase in plasma clearance of the hormone B) Decrease in half-life of the hormone C) Increase in hormone activity D) Increase in degree of negative feedback exerted by the hormone E) Increase in plasma reservoir for rapid replenishment of free hormone

E) Increase in plasma reservoir for rapid replenishment of free hormone

What is the cause of the decrease in calcium ion concentration? A) The increase in arterial pH resulting from the sodium bicarbonate infusion inhibited PTH 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

66. A patient presents with tachycardia and heat intolerance. You suspect Graves’ disease. Which of the following is not consistent with your diagnosis? A) Increased total and free T4 B) Suppressed plasma [TSH] C) Exophthalmos D) Goiter E) Decreased thyroid radioactive iodine uptake

E) Decreased thyroid radioactive iodine uptake

67. A 30-year-old woman is breastfeeding her infant. During suckling, which hormonal response is expected in the woman? A) Increased secretion of 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

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

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

``` 70. Dehydroepiandrosterone sulfate (DHEAS), the precursor for the high levels of estradiol that occur in pregnancy, is made in what tissue? A) Fetal adrenal gland B) Ovary of the mother C) Placenta D) Adrenal gland of the mother ```

D) Adrenal gland of the mother

71. What is the consequence of sporadic nursing of the neonate by the mother? A) An increase in prolactin-releasing hormone B) An increase in oxytocin C) Lack of birth control D) Lack of prolactin surge

D) Lack of prolactin surge

72. Which of the following would be associated with parallel changes in aldosterone and cortisol secretion? A) Addison’s disease B) Cushing’s disease C) Cushing’s syndrome (adrenal tumor) D) A low-sodium diet E) Administration of a converting enzyme inhibitor

A) Addison’s disease

73. A chronic increase in the plasma concentration of thyroxine-binding globulin (TBG) would result in which of the following? A) An increased delivery of T4 to target cells B) A decrease in plasma free [T4] C) An increase in the conversion of T4 to triiodothyronine (T3) in peripheral tissues D) An increase in TSH secretion E) No change in metabolic rate

E) No change in metabolic rate

74. RU486 causes abortion if it is administered before or soon after implantation. What is the specific effect of RU486? A) It binds to LH 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 FSH 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

75. A 55-year-old man has developed the syndrome of inappropriate antidiuretic hormone secretion due to carcinoma of the lung. Which physiological response would be expected? A) Increased plasma osmolality B) Inappropriately low urine osmolality (relative to plasma osmolality) C) Increased thirst D) Decreased secretion of ADH from the pituitary gland

D) Decreased secretion of ADH from the pituitary | gland

76. During pregnancy, the uterine smooth muscle is quiescent. During the ninth month of gestation, the uterine muscle becomes progressively more excitable. What factor contributes 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) PGE2 synthesis by the placenta decreases E) Activity of the fetus falls to low levels

B) Progesterone synthesis by the placenta decreases

77. A 20-year-old woman is not having menstrual cycles. Her plasma progesterone concentration is found to be minimal. What is the explanation for the low level of progesterone? A) LH secretion rate is elevated B) LH secretion rate is suppressed C) FSH secretion rate is suppressed D) No corpus luteum is present E) High inhibin concentration in the plasma has suppressed progesterone synthesis

D) No corpus luteum is present

``` 78. Before the preovulatory surge in LH, granulosa cells of the follicle secrete which hormone? A) Testosterone B) Progesterone C) Estrogen D) Inhibin ```

C) Estrogen

``` 81. Which hormone activates enzyme-linked receptors? A) ADH B) Insulin C) ACTH D) PTH E) Aldosterone ```

B) Insulin

82. Which of the following is produced by the trophoblast cells during the first 3 weeks of pregnancy? ``` A) Estrogen B) LH C) Oxytocin D) HCG E) None of the above ```

D) HCG

83. Which of the following is higher in the neonate than in the fetus? A) Flow through the foramen ovale B) Right atrial pressure C) Flow through the ductus arteriosus D) Aortic pressure

B) Right atrial pressure

84. Which finding is most likely in a patient who has myxedema? ``` A) Somnolence B) Palpitations C) Increased respiratory rate D) Increased cardiac output E) Weight loss ```

A) Somnolence

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) The neonate experienced in utero malnutrition B) The mother was malnourished during pregnancy C) The mother is diabetic, with poorly controlled hyperglycemia D) The mother is obese

C) The mother is diabetic, with poorly controlled | hyperglycemia

86. In the fetus, why can normal growth occur despite low Po2 levels? A) The concentration of hemoglobin A is increased in the fetus B) The hemoglobin of the fetus can carry more oxygen at lower Pco2 levels C) The oxyhemoglobin curve in the fetus is shifted to the left D) The mother has increased blood volume during pregnancy

C) The oxyhemoglobin curve in the fetus is shifted to | the left

87. Which of the following stimulates the secretion of PTH? A) An increase in extracellular calcium ion activity above the normal value B) An 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

``` 88. A 40-year-old woman consumes a high-potassium diet for several weeks. Which hormonal change is most likely to occur? A) Increased secretion of DHEA B) Increased secretion of cortisol C) Increased secretion of aldosterone D) Increased secretion of ACTH E) Decreased secretion of CRH ```

C) Increased secretion of aldosterone

``` 89. After implantation into the uterus, nutrition of the blastocyst comes from which structure? A) Placenta B) Decidua C) Glomerulosa cells D) Corpus luteum ```

B) Decidua

``` 90. Which hormone is not stored in its endocrine-producing gland? A) T4 B) PTH C) Aldosterone D) ACTH E) Insulin ```

C) Aldosterone

91. A young woman comes to the emergency department with a vertebral compression fracture. Radiographs of the spine indicate generalized demineralization. She is vegetarian, does not smoke or drink alcohol, and has a normal plasma potassium concentration of 5.4 mEq/L, a sodium concentration of 136 mEq/L, and a plasma calcium concentration of 7.0 mg/dl. Her vitamin D3 value is several times greater than normal, although her 1,25-dihydroxycholecalciferol concentration is at the lower limit of detectability. She has been in renal failure for the past 5 years and undergoes hemodialysis three times each week. What is the cause of her low 1,25-dihydroxycholecalciferol level? A) Metabolic acidosis B) Metabolic alkalosis C) She is unable to form 1,25-dihydroxycholecalciferol because of her extensive kidney disease D) She is undergoing dialysis with a dialysis fluid that does not contain calcium E) She is taking receiving calcium supplements

C) She is unable to form 1,25-dihydroxycholecalciferol | because of her extensive kidney disease

``` 92. The placenta is incapable of synthesizing which hormones? A) Estrogen B) Progesterone C) Androgens D) Estriol ```

C) Androgens

93. A neonate develops jaundice and has 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) The bilirubin concentration rises no further B) Hematocrit falls only slightly C) The mother, father, and neonate are all Rh-negative D) The mother has no history of hepatic dysfunction

C) The mother, father, and neonate are all Rh-negative

``` 94. Which finding would likely be reported in a patient with a deficiency in iodine intake? A) Weight loss B) Nervousness C) Increased sweating D) Increased synthesis of thyroglobulin E) Tachycardia ```

D) Increased synthesis of thyroglobulin

95. A 37-year-old woman presents to her physician with an enlarged thyroid gland and high plasma levels of T4 and T3. Which of the following is likely to be decreased? A) Heart rate B) Cardiac output C) Peripheral vascular resistance D) Ventilation rate E) Metabolic rate

C) Peripheral vascular resistance

96. 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) The metabolic rate will increase B) The rate of movement will decrease C) The formation of PGE2 will increase D) The rate of oxygen consumption will increase

B) The rate of movement will decrease

98. 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 GnRH by the hypothalamus, resulting in the inhibition of LH and FSH release by the anterior pituitary D) High levels of androgen compounds produce hypertrophic dysfunction of the prostate gland

C) High levels of androgen compounds inhibit the | secretion of GnRH by the hypothalamus, resulting in the inhibition of LH and FSH release by the anterior pituitary

``` 99. Cortisone is administered to a 30-year-old woman for the treatment of an autoimmune disease. Which of the following is most likely to occur? A) Increased ACTH secretion B) Increased cortisol secretion C) Increased insulin secretion D) Increased muscle mass E) Hypoglycemia between meals ```

C) Increased insulin secretion

100. In the hypothalamic-pituitary-gonadal axis of the female, what is the follicular cell type that produces inhibin? A) Cytotrophoblasts B) Synthiotrophoblasts C) Granulosa D) Thecal

C) Granulosa

101. 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 the above

A) Osteoclasts

102. Which statement about peptide or protein hormones is usually true? A) They have longer half-lives than steroid hormones B) They have receptors on the cell membrane C) They have a slower onset of action than both steroid and thyroid hormones D) They are not stored in endocrine-producing glands

B) They have receptors on the cell membrane

``` 104. Cortisol and GH are most dissimilar in their metabolic effects on which of the following? A) Protein synthesis in muscle B) Glucose uptake in peripheral tissues C) Plasma glucose concentration D) Mobilization of triglycerides ```

A) Protein synthesis in muscle

105. Why do infants of mothers who had adequate nutrition during pregnancy not require iron supplements or a diet rich in iron until about 3 months of age? A) Growth of the infant does not require iron until after the third 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 third month do not contain myoglobin

B) The fetal liver stores enough iron to meet the infant’s needs until the third month

``` 106. Cortisone is administered to a patient for the treatment of an autoimmune disease. Which of the following would least likely occur in response to the cortisone treatment? A) Hypertrophy of the adrenal glands B) Increased plasma levels of C-peptide C) Decreased CRH secretion D) Increased blood pressure E) Hyperglycemia ```

A) Hypertrophy of the adrenal glands

``` 107. Which symptom would least likely be associated with thyrotoxicosis? A) Tachycardia B) Increased appetite C) Somnolence D) Increased sweating E) Muscle tremor ```

C) Somnolence

108. If a male is born without a penis and testes, a defect is likely in which gene on the Y chromosome? A) ERE—estrogen response element B) ARE—androgen response element C) SRY—affecting Sertoli cells D) ERG—early response genes

C) SRY—affecting Sertoli cells

``` 109. Where does fertilization normally take place? A) Uterus B) Cervix C) Ovary D) Ampulla of the fallopian tubes ```

D) Ampulla of the fallopian tubes

110. Which finding is most likely to occur in a patient who has uncontrolled type 1 DM? 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

``` 111. GH secretion would most likely be suppressed under which condition? A) Acromegaly B) Gigantism C) Deep sleep D) Exercise E) Acute hyperglycemia ```

E) Acute hyperglycemia

``` 112. Pregnenolone is not in the biosynthetic pathway of which substance? A) Cortisol B) Estrogen C) Aldosterone D) 1,25(OH)2D E) DHEA ```

D) 1,25(OH)2D

113. Two days before the onset of menstruation, secretions of FSH and 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 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

114. Which condition contributes to “sodium escape” in persons with Conn’s syndrome? A) Decreased plasma levels of atrial natriuretic peptide B) Increased plasma levels of angiotensin II C) Decreased sodium reabsorption in the collecting tubules D) Increased arterial pressure

D) Increased arterial pressure

116. A 30-year-old woman reports to the clinic for a routine physical examination, which reveals she is pregnant. Her plasma levels of TSH are high, but her total T4 concentration (protein bound and free) is normal. Which of the following best reflects this patient’s clinical state? A) Graves’ disease B) Hashimoto’s disease C) A pituitary tumor that is secreting TSH D) A hypothalamic tumor that is secreting TRH E) The patient is taking thyroid extract

B) Hashimoto’s disease

117. A man has 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

118. Which component of the reproductive system has the most far-reaching effects on the physiology of the organism? A) /Y chromosomal effects B) X dose—one X chromosome versus two X chromosomes C) Gonadal steroid hormones D) Prenatal testosterone levels

C) Gonadal steroid hormones

119. 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

120. Birth control pills containing combinations of synthetic estrogen and progesterone compounds that are 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 LH secretion from the pituitary gland B) Prevention of development of the ovarian follicles C) Suppression of the function of the corpus luteum soon after it forms D) Prevention of normal development of the endometriu

A) Prevention of the preovulatory surge of LH secretion from the pituitary gland

121. Which of the following would be expected in a patient with a genetic deficiency of 11-β-hydroxysteroid dehydrogenase type II? A) Hyperkalemia B) Hypertension C) Increased plasma renin activity D) Increased plasma [aldosterone] E) Hyperglycemia

B) Hypertension

122. Which physiological response is greater for T3 than for T4? A) Secretion rate from the thyroid B) Plasma concentration C) Plasma half-life D) Affinity for nuclear receptors in target tissues E) Latent period for the onset of action in target tissues

D) Affinity for nuclear receptors in target tissues

123. A “birth control” compound for men has been sought for several decades. Which substance would provide effective sterility? A) A substance that mimics the actions of LH B) A substance that blocks the actions of inhibin C) A substance that blocks the actions of FSH D) A substance that mimics the actions of GnRH

C) A substance that blocks the actions of FSH

124. For milk to flow from the nipple of the mother into the mouth of the nursing infant, what 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 the above

C) Oxytocin secretion from the posterior pituitary | must take place

125. Failure of the ductus arteriosus to close is a common developmental defect. Which condition 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

127. When compared with the late-evening values typically observed in normal subjects, plasma levels of both ACTH and cortisol would be expected to be higher in which persons? A) Normal subjects after waking in the morning B) Normal subjects who have taken 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

``` 128. Which of the following conditions or hormones would most likely increase GH secretion? A) Hyperglycemia B) Exercise C) Somatomedin D) Somatostatin E) Aging ```

B) Exercise

130. What would be associated with parallel changes in aldosterone and cortisol secretion? A) Addison’s disease B) Cushing’s disease C) Cushing’s syndrome (ectopic ACTH-producing tumor) D) A high-sodium diet E) Administration of a converting enzyme inhibitor

A) Addison’s disease

``` 131. 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

132. A 59-year-old woman has osteoporosis, hypertension, hirsutism, and hyperpigmentation. Magnetic resonance imaging indicates that the pituitary gland is not enlarged. Which condition is most consistent with these findings? ``` A) Pituitary ACTH-secreting tumor B) Ectopic ACTH-secreting tumor C) Inappropriately high secretion rate of CRH D) Adrenal adenoma E) Addison’s disease ```

B) Ectopic ACTH-secreting tumor

135. 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 phenomenon? 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

136. What causes 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

137. What does not increase when insulin binds to its receptor? A) Fat synthesis in adipose tissue B) Protein synthesis in muscle C) Glycogen synthesis D) Gluconeogenesis in the liver E) Intracellular tyrosine kinase activity

D) Gluconeogenesis in the liver

``` 138. Release of which hormone is an example of neuroendocrine secretion? A) GH B) Cortisol C) Oxytocin D) Prolactin E) ACTH ```

C) Oxytocin

139. During the week after ovulation, the endometrium increases in thickness to 5 to 6 millimeters. What stimulates this increase in thickness? A) LH B) Estrogen from the corpus luteum C) Progesterone from the corpus luteum D) FSH

C) Progesterone from the corpus luteum

``` 140. Inhibition of the iodide pump would be expected to cause which change? A) Increased synthesis of T4 B) Increased synthesis of thyroglobulin C) Increased metabolic rate D) Decreased TSH secretion E) Extreme nervousness ```

B) Increased synthesis of thyroglobulin

141. Before implantation, the blastocyst obtains its nutrition from 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

``` 142. Which pituitary hormone has a chemical structure most similar to that of ADH? A) Oxytocin B) ACTH C) TSH D) FSH E) Prolactin ```

A) Oxytocin

``` 143. Which option would not be efficacious in the treatment of patients with type 2 diabetes? A) Glucocorticoids B) Insulin injections C) Thiazolidinediones D) Sulfonylureas E) Weight loss ```

A) Glucocorticoids

144. Which of the following is most likely to occur in the early stages of type 2 diabetes? A) Increased insulin sensitivity B) Decreased hepatic glucose output C) Increased plasma levels of C-peptide D) Increased plasma [β-hydroxybutyric acid] E) Hypovolemia

C) Increased plasma levels of C-peptide

145. 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

147. 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 hormone would most likely increase in this patient? A) ACTH B) GH C) Prolactin D) LH E) TSH

C) Prolactin

``` 148. Which of the following is not produced by osteoblasts? A) Alkaline phosphatase B) RANK ligand C) Collagen D) Pyrophosphate E) Osteoprotegerin ```

D) Pyrophosphate

150. 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) A normal secretory pattern of GnRH B) Normal levels of inhibin C) Suppressed levels of FSH D) Absence of Leydig cells

A) A normal secretory pattern of GnRH

``` 151. What is hormone 1? A) TRH B) TSH C) T4 D) ACTH E) Cortisol ```

B) TSH

``` 152. What is hormone 2? A) TSH B) T4 C) CRH D) ACTH E) Cortisol ```

C) CRH

endocrine and reproductive system Flashcards

(128 cards)