Flashcards in endocrine-adrenal cortex Deck (22)
what are the 3 layers of the adrenal cortex
what do the 3 zones of the adrenal cortex secrete
zona glomerulosa- mineralcorticoids
zona fasciculata- glucocorticoids
zona retircularis- androgens
why do you seen muscle weakness and thin extremeties in Cushing's syndrome
cortisol breaks muscle producing amino acids for gluconeogenesis
why do you see abdominal striae in Cushing's syndrome
due to impaired synthesis of collagen with thinning of skin
Cushing's syndrome with bilateral atrophic adrenal glands..whats the cause
exogenous corticosteroid use
Cushing's syndrome with unilateral atrophic adrenal gland..whats the cause?
primary adrenal adenoma, hyperplasia or carcinoma
Cushing's syndrome with bilateral hypertrophic adrenal glands..whats the cause?
ACTH secreting pituitary adenoma OR paraneoplastic ACTH secretion
how could you tell the difference between an ACTH secreting pituitary adenoma or a paraneoplastic ACTH secreting tumor
high dose dexamethasone (cortisol analog) which suppresses ACTH production by a pituitary adenoma (cortisol levels will decrease) but fails to suppress ectopic ACTH from a paraneoplastic source
what is conn syndrome
will you see metabolic acidosis or alkalosis in conn syndrome? why?
metabolic alkalosis because aldosterone causes secretion of H in the distal tubules and collecting duct
what is the most common cause of primary hyperaldosteronism
sporadic adrenal hyperplasia
in primary hyperaldosteronism, will the renin levels be elevated or depressed
depressed (high BP down regulates renin via negative feedback)
when will you see high aldosterone and high renin
in secondary hyperaldosteronism seen with activation of the renin-angiotensin system (ex. in renovascular HTN or CHF)
what is the most common cause of congenital adrenal hyperplasia
inherited 21 hydroxylase deficiency
production of __ and ___ requires 21 hydroxylase
required for production of aldosterone and corticosteroids
what do you see bilateral adrenal hyperplasia in CAH
deficiency of cortisol causes increased ACTH (due to lack of negative feedback)
what are the consequences of the increase in the sex steroid production seen in CAH
clitoral enlargement (females) or prcocious puberty (males) due to excess androgens
what is syndrome
"hemorrhage necrosis of the adrenal glands classically due to DIC in young children"
waterhouse friderichsen syndrome
what infection classically precedes waterhouse friderichsen syndrome?
N. meningitidis infection
what is addison's disease
chronic adrenal insufficiency
what is the most common cause of addison's disease in western countries? developing world?
western countries-autoimmune destruction