Unit 2 - Aldosterone and Natriuretic Polypeptide Flashcards
What is the chemical nature of aldosterone?
mineralcorticoid
What part of the adrenal gland secretes aldosterone?
zona glomerulosa
What are the major triggers of aldosterone secretion?
decrease in blood pressure and glomerular filtration rate
What are the major functions of aldosterone?
sustaining extracellular fluid volume by conserving body sodium and preventing the overload of potassium by accelerating its excretion
What does the decrease in blood pressure and glomerular filtration rate stimulate the release of?
Renin from juxtaglomerular cells
What is the function of Renin?
it catalyzes the conversion of angiotensinogen and angiotensin I
What is ACE and what does it do?
angiotensin converting enzyme which converts angiotensin I into angiotensin II ad III
What are the cellular effects of aldosterone?
stimulation of ATP production, stimulate the permeability of sodium channels, and are involved in the synthesis of Na pumps to pump Na out
Why is a bilateral adrenalectomy fatal?
Removing both adrenal glands causes a decrease in aldosterone which causes Na loss and K and H retention which leads to water loss (both extracellular and intracellular fluid) which leads to peripheral circulatory failure/renal failure
What is the chemical nature of ANP?
natriuretic peptide
What is ANP released from?
atrial myocytes
What are the causes for secretion of ANP?
it is secreted in response to atrial stretch due to hypervolemia, hypertension, or hypernatremia
What is the function of ANP?
it reduces Na and fluid levels; natriuresis and diuresis
What is Addison’s like disease?
Adrenocortical insufficiency (hypoadrenocorticism)
What are symptoms commonly seen with Adisson’s-like disease?
it imitates symptoms of other diseases; hyponatremia, hyperkalemia, decrease in Na/K ratio, increase in ACTH, decrease in cortisol, decrease in aldosterone, acidemia
