Aldosterone and RAAS Flashcards
where is aldosterone secreted from
the adrenal cortex
when is aldosterone secreted
in response to rising [K+] or falling [Na+] in blood
OR activation of RAAS
describe the effect of aldosterone
stimulates Na+ reabsorption and K+ secretion
what secondary effect does aldosterone have by its effect on Na
increased Na reabsorption contributes to increased blood volume and pressure
what parts of the nephron does aldosterone act on
only the distal tubule and collecting ducts
where is renin released from
granular cells in the juxtaglomerular apparatus
what acts to promote secretion of renin
decreased plasma NaCl, decreased ECF volume, decreased arterial BP
what is the role of renin
converts angiotensinogen to angiotensin I
describe the effects of angiotensin II
increased vasopressin(ADH), increased thirst, increased arteriolar vasoconstriction
what does the RAAS act to do
to correct decreased NaCl in blood, decreased ECF and decreased arterial BP
describe how aldosterone increases Na reabsorption and K secretion
by increasing number of Na/H/K pumps at basolateral membrane, which result in Na out of the cell(reabsorption) and K int the cell(secreted)
where is atrial natriuretic peptide(ANP) produced and secreted in response to what
produced in heart, released when myocytes are stretched due to increased circulating plasma volume
describe the action of ANP
promotes excretion of Na+ ad diuresis, therefore decreasing plasma volume
how does ANP bring about its effect
by inhibiting RAAS
