kidneys and urinary Flashcards
what % of cardiac output do kidney receive
20-25
start of the urinary plumbing
calyx
nephrons are mostly in the
cortex, approx 1 million
what are nephrons
smallest unit that can preform all the functions of the kidney - ie forming urine
each nephron has 2 components
vascular component and tubular
vascular componnet
glomerulus; renal artery, afferent arteriole, then flows through ball like glomerulus, then efferent (existing) arteriole and into peritubulues which surround tubular part of nephron and supply blood exchange
what are the long peritubules that dip into the medullas callled
vasa recta
in response to atria being stretched
ANP- atrial natriuretic petide
what is ANP
- inhibits RAAS antagonist for aldosterone - so this inhibits Na+ reabsorption and excretes more salt - in response to a stretched atrial - increases GFR= more water loss - inhibits renin from kidneys
what’s natriuresis
excreting excess salt
what else does ANP cause
- increase GFR
- inhibit renin from kidneys
- it is here to decrease blood pressure and loss more water and salt
- afferent arteriole dilation
- sympathetic nervous system = less heart rate
aldosterone
main mineralocorticoid steroid hormone produced by adrenal cortex- cause reabsorption of sodium
- acts by increasing the transcription of new NA+ and K+ pumps
- save NA+ , excrete K+
how is aldosterone excreted?
from the adrenal cortex upon the stimulus of RAAS ( low blood pressure- kidneys release renin)
how would aldosterone release get inhibited?
inhibition of RAAS- ANP,
depletion of K+ in body
Aldosterone
raises blood pressure and lowers K+ levels
