Question 1

Which of the following hormones acts by an inositol 1,4,5-triphosphate ( $\left.\mathrm{IP}_{3}\right)-\mathrm{Ca}^{2+}$ mechanism of action?

Accepted Answer

A)  1,25-Dihydroxycholecalciferol 
B)  Progesterone 
C)  Insulin 
D)  Parathyroid hormone (PTH) 
E)  Gonadotropin-releasing hormone $(\mathrm{GnRH})$ 
A)  1,25-Dihydroxycholecalciferol 
B)  Progesterone 
C)  Insulin 
D)  Parathyroid hormone (PTH) 
E)  Gonadotropin-releasing hormone $(\mathrm{GnRH})$ E

Question 2

Secretion of oxytocin is increased by

Accepted Answer

A)  milk ejection 
B)  dilation of the cervix 
C)  increased prolactin levels 
D)  increased extracellular fluid (ECF) volume 
E)  increased serum osmolarity 
A)  milk ejection 
B)  dilation of the cervix 
C)  increased prolactin levels 
D)  increased extracellular fluid (ECF) volume 
E)  increased serum osmolarity B

Question 3

Use the graph below, which shows changes during the menstrual cycle, to answer the following Questions
  
-The increase shown at point $A$ is caused by the effect of

Accepted Answer

A)  estrogen on the anterior pituitary 
B)  progesterone on the hypothalamus 
C)  follicle-stimulating hormone (FSH) on the ovary 
D)  luteinizing hormone (LH) on the anterior pituitary 
E)  prolactin on the ovary 
A)  estrogen on the anterior pituitary 
B)  progesterone on the hypothalamus 
C)  follicle-stimulating hormone (FSH) on the ovary 
D)  luteinizing hormone (LH) on the anterior pituitary 
E)  prolactin on the ovary B

Question 4

Which of the following inhibits the secretion of growth hormone by the anterior pituitary?

Accepted Answer

A)  Sleep 
B)  Stress 
C)  Puberty 
D)  Somatomedins 
E)  Starvation
F) Hypoglycemia 
A)  Sleep 
B)  Stress 
C)  Puberty 
D)  Somatomedins 
E)  Starvation
F) Hypoglycemia

Question 5

A 41-year-old woman has hypocalcemia, hyperphosphatemia, and decreased urinary phosphate excretion. Injection of parathyroid hormone (PTH) causes an increase in urinary cyclic adenosine monophosphate (cAMP). The most likely diagnosis is

Accepted Answer

A)  primary hyperparathyroidism 
B)  vitamin $\mathrm{D}$ intoxication 
C)  vitamin D deficiency 
D)  hypoparathyroidism after thyroid surgery 
E)  pseudohypoparathyroidism 
A)  primary hyperparathyroidism 
B)  vitamin $\mathrm{D}$ intoxication 
C)  vitamin D deficiency 
D)  hypoparathyroidism after thyroid surgery 
E)  pseudohypoparathyroidism

Question 6

Which of the following hormones originates in the anterior pituitary?

Accepted Answer

A)  Dopamine 
B)  Growth hormone-releasing hormone (GHRH) 
C)  Somatostatin 
D)  Gonadotropin-releasing hormone (GnRH) 
E)  Thyroid-stimulating hormone (TSH)
F) Oxytocin
(G) Testosterone 
A)  Dopamine 
B)  Growth hormone-releasing hormone (GHRH) 
C)  Somatostatin 
D)  Gonadotropin-releasing hormone (GnRH) 
E)  Thyroid-stimulating hormone (TSH)
F) Oxytocin
(G) Testosterone

Question 7

Which step in steroid hormone biosynthesis occurs in the accessory sex target tissues of the male and is catalyzed by $5 \alpha$-reductase?

Accepted Answer

A)  Cholesterol $\rightarrow$ pregnenolone 
B)  Progesterone $\rightarrow$ 11-deoxycorticosterone 
C)  17-Hydroxypregnenolone $\rightarrow$ dehydroepiandrosterone 
D)  Testosterone $\rightarrow$ estradiol 
E)  Testosterone $\rightarrow$ dihydrotestosterone 
A)  Cholesterol $\rightarrow$ pregnenolone 
B)  Progesterone $\rightarrow$ 11-deoxycorticosterone 
C)  17-Hydroxypregnenolone $\rightarrow$ dehydroepiandrosterone 
D)  Testosterone $\rightarrow$ estradiol 
E)  Testosterone $\rightarrow$ dihydrotestosterone

Question 8

Which step in steroid hormone biosynthesis is stimulated by adrenocorticotropic hormone (ACTH)?

Accepted Answer

A)  Cholesterol $\rightarrow$ pregnenolone 
B)  Progesterone $\rightarrow$ 11-deoxycorticosterone 
C)  17-Hydroxypregnenolone $\rightarrow$ dehydroepiandrosterone 
D)  Testosterone $\rightarrow$ estradiol 
E)  Testosterone $\rightarrow$ dihydrotestosterone 
A)  Cholesterol $\rightarrow$ pregnenolone 
B)  Progesterone $\rightarrow$ 11-deoxycorticosterone 
C)  17-Hydroxypregnenolone $\rightarrow$ dehydroepiandrosterone 
D)  Testosterone $\rightarrow$ estradiol 
E)  Testosterone $\rightarrow$ dihydrotestosterone

Question 9

Which of the following hormones acts on its target tissues by a steroid hormone mechanism of action?

Accepted Answer

A)  Thyroid hormone 
B)  Parathyroid hormone (PTH) 
C)  Antidiuretic hormone (ADH) on the collecting duct 
D)  $\beta_{1}$ adrenergic agonists 
E)  Glucagon 
A)  Thyroid hormone 
B)  Parathyroid hormone (PTH) 
C)  Antidiuretic hormone (ADH) on the collecting duct 
D)  $\beta_{1}$ adrenergic agonists 
E)  Glucagon

Question 10

The source of estrogen during the second and third trimesters of pregnancy is the

Accepted Answer

A)  corpus luteum 
B)  maternal ovaries 
C)  fetal ovaries 
D)  placenta 
E)  maternal ovaries and fetal adrenal gland
F) maternal adrenal gland and fetal liver
G) fetal adrenal gland, fetal liver, and placenta 
A)  corpus luteum 
B)  maternal ovaries 
C)  fetal ovaries 
D)  placenta 
E)  maternal ovaries and fetal adrenal gland
F) maternal adrenal gland and fetal liver
G) fetal adrenal gland, fetal liver, and placenta

Question 11

A 61-year-old woman with hyperthyroidism is treated with propylthiouracil. The drug reduces the synthesis of thyroid hormones because it inhibits oxidation of

Accepted Answer

A)  Triiodothyronine $\left(\mathrm{T}_{3}\right)$ 
B)  Thyroxine $\left(\mathrm{T}_{4}\right)$ 
C)  Diiodotyrosine (DIT) 
D)  Thyroid-stimulating hormone (TSH) 
E)  Iodide ( $\mathrm{I}^{-}$) 
A)  Triiodothyronine $\left(\mathrm{T}_{3}\right)$ 
B)  Thyroxine $\left(\mathrm{T}_{4}\right)$ 
C)  Diiodotyrosine (DIT) 
D)  Thyroid-stimulating hormone (TSH) 
E)  Iodide ( $\mathrm{I}^{-}$)

Question 12

Use the graph below, which shows changes during the menstrual cycle, to answer the following Questions
  
-The source of the increase in concentration indicated at point $\mathrm{C}$ is the

Accepted Answer

A)  hypothalamus 
B)  anterior pituitary 
C)  corpus luteum 
D)  ovary 
E)  adrenal cortex 
A)  hypothalamus 
B)  anterior pituitary 
C)  corpus luteum 
D)  ovary 
E)  adrenal cortex

Question 13

Which of the following functions of the Sertoli cells mediates negative feedback control of follicle-stimulating hormone (FSH) secretion?

Accepted Answer

A)  Synthesis of inhibin 
B)  Synthesis of testosterone 
C)  Aromatization of testosterone 
D)  Maintenance of the blood-testes barrier 
A)  Synthesis of inhibin 
B)  Synthesis of testosterone 
C)  Aromatization of testosterone 
D)  Maintenance of the blood-testes barrier

Question 14

A 39-year-old man with untreated diabetes mellitus type I is brought to the emergency room. An injection of insulin would be expected to cause an increase in his

Accepted Answer

A)  urine glucose concentration 
B)  blood glucose concentration 
C)  blood $\mathrm{K}^{+}$concentration 
D)  blood $\mathrm{pH}$ 
E)  breathing rate 
A)  urine glucose concentration 
B)  blood glucose concentration 
C)  blood $\mathrm{K}^{+}$concentration 
D)  blood $\mathrm{pH}$ 
E)  breathing rate

Question 15

Which of the following results from the action of parathyroid hormone (PTH) on the renal tubule?

Accepted Answer

A)  Inhibition of $1 \alpha$-hydroxylase 
B)  Stimulation of $\mathrm{Ca}^{2+}$ reabsorption in the distal tubule 
C)  Stimulation of phosphate reabsorption in the proximal tubule 
D)  Interaction with receptors on the luminal membrane of the proximal tubular cells 
E)  Decreased urinary excretion of cyclic adenosine monophosphate (CAMP) 
A)  Inhibition of $1 \alpha$-hydroxylase 
B)  Stimulation of $\mathrm{Ca}^{2+}$ reabsorption in the distal tubule 
C)  Stimulation of phosphate reabsorption in the proximal tubule 
D)  Interaction with receptors on the luminal membrane of the proximal tubular cells 
E)  Decreased urinary excretion of cyclic adenosine monophosphate (CAMP)

Question 16

Which step in steroid hormone biosynthesis, if inhibited, blocks the production of all androgenic compounds but does not block the production of glucocorticoids?

Accepted Answer

A)  Cholesterol $\rightarrow$ pregnenolone 
B)  Progesterone $\rightarrow$ 11-deoxycorticosterone 
C)  17-Hydroxypregnenolone $\rightarrow$ dehydroepiandrosterone 
D)  Testosterone $\rightarrow$ estradiol 
E)  Testosterone $\rightarrow$ dihydrotestosterone 
A)  Cholesterol $\rightarrow$ pregnenolone 
B)  Progesterone $\rightarrow$ 11-deoxycorticosterone 
C)  17-Hydroxypregnenolone $\rightarrow$ dehydroepiandrosterone 
D)  Testosterone $\rightarrow$ estradiol 
E)  Testosterone $\rightarrow$ dihydrotestosterone

Question 17

Which of the following causes increased aldosterone secretion?

Accepted Answer

A)  Decreased blood volume 
B)  Administration of an inhibitor of angiotensin-converting enzyme (AC
E)  
C)  Hyperosmolarity 
D)  Hypokalemia 
A)  Decreased blood volume 
B)  Administration of an inhibitor of angiotensin-converting enzyme (AC
E)  
C)  Hyperosmolarity 
D)  Hypokalemia

Question 18

A 16-year-old, seemingly normal female is diagnosed with androgen insensitivity disorder. She has never had a menstrual cycle and is found to have a blind-ending vagina; no uterus, cervix, or ovaries; a $46 \mathrm{XY}$ genotype; and intra-abdominal testes. Her serum testosterone is elevated. Which of the following characteristics is caused by lack of androgen receptors?

Accepted Answer

A)  $46 \mathrm{XY}$ genotype 
B)  Testes 
C)  Elevated serum testosterone 
D)  Lack of uterus and cervix 
E)  Lack of menstrual cycles 
A)  $46 \mathrm{XY}$ genotype 
B)  Testes 
C)  Elevated serum testosterone 
D)  Lack of uterus and cervix 
E)  Lack of menstrual cycles

Question 19

Selective destruction of the zona glomerulosa of the adrenal cortex would produce a deficiency of which hormone?

Accepted Answer

A)  Aldosterone 
B)  Androstenedione 
C)  Cortisol 
D)  Dehydroepiandrosterone 
E)  Testosterone 
A)  Aldosterone 
B)  Androstenedione 
C)  Cortisol 
D)  Dehydroepiandrosterone 
E)  Testosterone

Question 20

Which of the following explains the suppression of lactation during pregnancy?

Accepted Answer

A)  Blood prolactin levels are too low for milk production to occur 
B)  Human placental lactogen levels are too low for milk production to occur 
C)  The fetal adrenal gland does not produce sufficient estriol 
D)  Blood levels of estrogen and progesterone are high 
E)  The maternal anterior pituitary is suppressed 
A)  Blood prolactin levels are too low for milk production to occur 
B)  Human placental lactogen levels are too low for milk production to occur 
C)  The fetal adrenal gland does not produce sufficient estriol 
D)  Blood levels of estrogen and progesterone are high 
E)  The maternal anterior pituitary is suppressed

Which of the following hormones acts by an inositol 1,4,5-triphosphate ( $\left.\mathrm{IP}_{3}\right)-\mathrm{Ca}^{2+}$ mechanism of action?

Secretion of oxytocin is increased by

Use the graph below, which shows changes during the menstrual cycle, to answer the following Questions -The increase shown at point $A$ is caused by the effect of

Which of the following inhibits the secretion of growth hormone by the anterior pituitary?

A 41-year-old woman has hypocalcemia, hyperphosphatemia, and decreased urinary phosphate excretion. Injection of parathyroid hormone (PTH) causes an increase in urinary cyclic adenosine monophosphate (cAMP). The most likely diagnosis is

Which of the following hormones originates in the anterior pituitary?

Which step in steroid hormone biosynthesis occurs in the accessory sex target tissues of the male and is catalyzed by $5 \alpha$ -reductase?

Which step in steroid hormone biosynthesis is stimulated by adrenocorticotropic hormone (ACTH)?

Which of the following hormones acts on its target tissues by a steroid hormone mechanism of action?

The source of estrogen during the second and third trimesters of pregnancy is the

A 61-year-old woman with hyperthyroidism is treated with propylthiouracil. The drug reduces the synthesis of thyroid hormones because it inhibits oxidation of

Which of the following functions of the Sertoli cells mediates negative feedback control of follicle-stimulating hormone (FSH) secretion?

A 39-year-old man with untreated diabetes mellitus type I is brought to the emergency room. An injection of insulin would be expected to cause an increase in his

Which of the following results from the action of parathyroid hormone (PTH) on the renal tubule?

Which step in steroid hormone biosynthesis, if inhibited, blocks the production of all androgenic compounds but does not block the production of glucocorticoids?

Which of the following causes increased aldosterone secretion?

Selective destruction of the zona glomerulosa of the adrenal cortex would produce a deficiency of which hormone?

Which of the following explains the suppression of lactation during pregnancy?

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Exam 7: Endocrine Physiology

Which of the following hormones acts by an inositol 1,4,5-triphosphate ( IP3)−Ca2+\left.\mathrm{IP}_{3}\right)-\mathrm{Ca}^{2+}IP3​)−Ca2+ mechanism of action?

Secretion of oxytocin is increased by

Use the graph below, which shows changes during the menstrual cycle, to answer the following Questions -The increase shown at point AAA is caused by the effect of

Which of the following inhibits the secretion of growth hormone by the anterior pituitary?

A 41-year-old woman has hypocalcemia, hyperphosphatemia, and decreased urinary phosphate excretion. Injection of parathyroid hormone (PTH) causes an increase in urinary cyclic adenosine monophosphate (cAMP). The most likely diagnosis is

Which of the following hormones originates in the anterior pituitary?

Which step in steroid hormone biosynthesis occurs in the accessory sex target tissues of the male and is catalyzed by 5α5 \alpha5α -reductase?

Which step in steroid hormone biosynthesis is stimulated by adrenocorticotropic hormone (ACTH)?

Which of the following hormones acts on its target tissues by a steroid hormone mechanism of action?

The source of estrogen during the second and third trimesters of pregnancy is the

A 61-year-old woman with hyperthyroidism is treated with propylthiouracil. The drug reduces the synthesis of thyroid hormones because it inhibits oxidation of

Use the graph below, which shows changes during the menstrual cycle, to answer the following Questions -The source of the increase in concentration indicated at point C\mathrm{C}C is the

Which of the following functions of the Sertoli cells mediates negative feedback control of follicle-stimulating hormone (FSH) secretion?

A 39-year-old man with untreated diabetes mellitus type I is brought to the emergency room. An injection of insulin would be expected to cause an increase in his

Which of the following results from the action of parathyroid hormone (PTH) on the renal tubule?

Which step in steroid hormone biosynthesis, if inhibited, blocks the production of all androgenic compounds but does not block the production of glucocorticoids?

Which of the following causes increased aldosterone secretion?

Selective destruction of the zona glomerulosa of the adrenal cortex would produce a deficiency of which hormone?

Which of the following explains the suppression of lactation during pregnancy?

Cell Physiology

Neurophysiology

Cardiovascular Physiology

Respiratory Physiology

Renal and Acidbase Physiology

Gastrointestinal Physiology

Comprehensive Examination

Filters

Which of the following hormones acts by an inositol 1,4,5-triphosphate ( $\left.\mathrm{IP}_{3}\right)-\mathrm{Ca}^{2+}$ mechanism of action?

Use the graph below, which shows changes during the menstrual cycle, to answer the following Questions -The increase shown at point $A$ is caused by the effect of

Which step in steroid hormone biosynthesis occurs in the accessory sex target tissues of the male and is catalyzed by $5 \alpha$ -reductase?