Quiz 43: The Adrenal Glands

A 25-year-old woman sees her physician because of hirsutism (inappropriate hair growth)and excessive acne.During examination,her blood pressure is 150/90 mm Hg (elevated).Blood work reveals normal Na⁺ levels but low/normal K⁺ levels.Testosterone and dihydrotestosterone (DHT)levels are in the high end of the normal range,and the levels of dehydroepiandrosterone sulfate (DHEAS)and adrenocorticotropic hormone (ACTH)are moderately elevated.Her physician suspects late-onset congenital adrenal hyperplasia resulting from subnormal activity of an adrenal enzyme.The subnormal activity of which enzyme explains both the elevated adrenal androgens (e.g.,DHEAS)and hypertension (elevated blood pressure)? A)CYP11B1 B)CYP17 C)CYP21A2 D)CYP11B2 E)CYP11A1

A 25-year-old woman sees her physician because of hirsutism (inappropriate hair growth)and excessive acne.During examination,her blood pressure is 150/90 mm Hg (elevated).Blood work reveals normal Na⁺ but low/normal K⁺ levels.Testosterone and dihydrotestosterone (DHT)levels are in the high end of the normal range,and levelso f DHEAS and ACTH are moderately elevated.Her physician suspects late-onset congenital adrenal hyperplasia resulting from subnormal activity of an adrenal enzyme.The "hyperplasia" associated with congenital adrenal hyperplasia is caused by elevated levels of: A)DHEAS. B)Cortisol. C)ACTH. D)Aldosterone. E)Deoxycorticosterone (DOC).

The adrenal medulla synthesizes catecholamines.The first enzyme in the catecholamine synthesis pathway,tyrosine hydroxylase,is stimulated by: A)Cortisol. B)Epinephrine. C)Norepinephrine. D)Acetylcholine. E)Nitric oxide.

Exercise increases catecholamine release.Stimulation of -adrenergic receptors specifically leads to: A)An increase in insulin secretion. B)Vasodilation of skeletal muscle arterioles. C)Vasoconstriction of splanchnic arterioles. D)Vasodilation of veins and lymphatic vessels. E)A positive inotropic effect on cardiac function.

ACTH has rapid,intermediate,and longer term effects on the function of the zona fasciculata.Which of the following is a target of rapid effects? A)Adrenal hypertrophy. B)Cortisol secretion. C)Steroidogenic acute regulatory (StAR)protein activation. D)CYP21A2 expression. E)Low-density lipoprotein (LDL)receptor expression.

The zona glomerulosa is notable for its absence of the following enzyme: A)CYP17 B)CYP11B2 C)CYP21A2 D)CYP11A1 E)3β-Hydroxysteroid dehydrogenase (3 HSD)

Cortisol is considered a "stress hormone." One of its direct actions that help an individual survive a physiological stress (e.g.,surgery)is: A)To increase hepatic gluconeogenesis. B)To increase skeletal muscle protein synthesis. C)To increase hepatic lipogenesis. D)To decrease adipose tissue lipolysis. E)To increase hepatic glycolysis.

Cortisol can bind to both the glucocorticoid receptor and the mineralocorticoid receptor.In the cells of the distal nephron,cortisol is prevented from binding to the mineralocorticoid receptor by: A)Competitive inhibition by aldosterone. B)Glucuronide conjugation. C)Conversion to cortisone. D)Rapid excretion. E)Binding to heat shock chaperone proteins.

A patient has been receiving immunosuppressive doses of glucocorticoids for 6 months.At the end of this therapy,the dosage of the hormone must be slowly tapered down over a period of weeks.This is because of the development of: A)Adrenal atrophy. B)Pituitary hypertrophy. C)Upregulation of glucocorticoid receptors. D)Elevated ACTH levels. E)Increased levels of circulating cortisol-binding globulin (CBG).

Cushing's disease is caused by an ACTH-oversecreting pituitary tumor.One of the effects of this is: A)Increased skeletal muscle mass. B)Decreased catecholamine responsiveness in the heart. C)Anorexia. D)Insulin resistance. E)Decreased glucagon responsiveness in adipose tissue.