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Flashcards in salt and water balance 2 Deck (6):

what is aldosterone released in response to?

high K+

angiotensin 2 acting on adrenal glands


describe the action of aldosterone

aldosterone once in the kidney binds to MR, causing insertion of ENaC channels. This allows Na+ to pass through and get reabsorbed into the blood


describe the difference between the regulation of ECF volume and osmolality

osmolality = regulated tightly by changes in renal water handling (ADH mediator)

ECF volume = regulated by changes in renal Na+ handling varies throughout a day (mediator = renin-angiotensin & SNS)


what increases Na+ reabsorption

- RAA system


what decreases Na+ reabsorption and describe its action

- blocks ENaC channel and inhibits Na/K/ATPase
- inhibits aldosterone release
- inhibits renin release
- vasodilates afferent arterioles (increasing GFR)


define the receptors that sense the change and result in the release of ADH

increased osmolality = hypothalamic osmoreceptors

decreased BP = carotid and aortic baroreceptors

decreased stretch due to low BV = atrial stretch receptors