Adrenals Flashcards
What stimulates the renin release in the renin angiotensin aldosterone system? (RAAS)
decreased perfusion to the kidney stimulates renin release
what is the role of renin in RAAS?
renin catalyzes the conversion of angiotensin to angiotensin I (note: ACE converts I to II )
what does angiotensin II do?
vasoconstriction
secretion of aldosterone
ADH and AVP from posterior pituitary
increase reabsorption of Na+ and secretion of K+ from kidneys
which of the following is NOT a stimulus for aldosterone secretion?
a. angiotensin II
b. elevation in serum K+
c. ACTH
d. SNS stimulation
SNS stimulation - this is only for catecholamines and also cortisol
which of the following is NOT an effect of catecholamines?
a. increase contractile force of the heart
b. bronchodilation
c. vasodilation of skin
d. increased heart rate
vasodilation of the skin
A patient is given a high dose of dexamethasone. What would you expect if the patient was experiencing ectopic production of ACTH?
Urinary cortisol would remain unchanged in response to dexamethasone.
how can you quickly differentiate between addisons disease (primary chronic adrenal insufficiency) and secondary adrenocortical insufficiency?
hyperpigmentation, hyperkalemia, hyponatremia will be present in addisons but not secondary adrenocortical insufficiency
what is primary hyperaldosteronism?
uncommon syndrome characterized by excess aldosterone causes sodium retention, K+ excretion so hypertension and hypokalemia.
An adrencocortical neoplasm (an adenoma that secretes aldosterone) can cause primary hyperaldosteroism. What is the name for this syndrome?
conn syndrome
what is secondary hyperaldosteronism?
aldosterone relesae in response to activation of the renin angiotensin system, increased plasma renin
what is the most common enzyme deficiency in congenital adrenal hyperplasia CAH?
21-hydroxylase
results in mild or complete loss of cortisol production
in CAH, differentiate between classic (affects newborn) types: salt wasting nad simple virilizing
salt wasting: complete inactivation of 21-hydroxylase
simple virilzing: significantly reduced function
what is the most common form of CAH?
late-onset (aka non-classic)
what is pheochromocytoma?
rare tumor of chromaffin cells. secrete elevated catecholamines. hypertension.
what are 3 things you could suspect if a patient had elevated cortisol?
cushing disease/syndrome
stress
hyperthyroidism
