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