Excretory system Flashcards
what are the functions of the kidney
excretes waste (urea, ammonia) maintains homeostasis of fluid vol in body and solute composition helps control plasma ph
functional unit of kidney is..
nephron
capillary beds of the nephron is?
glomerulus (where blood will flow into)
what is the renal corpuscle?
glomerulus + Bowmans capsule
what is the fluid called when it goes into Bowmans capsule?
filtrate or primary urine.. it then moves to the proximal tubule where most abs occurs
where does the filtrate flow after proximal tubule?
loop of henle..which will dip into medulla
what is the function of loop of henle?
inc concentration of solute and therefore will inc the osmotic pressure of the medulla.
(proximal tubule: reduces amount of filtrate in nephron (change the solute composition but it will NOT change osmolarity)
what happens due to high osmotic pressure in medulla?
water comes out of loop of henle into the medulla(passively)
descending loop of henle has low salt perm which means
filtrate osmolarity goes up
ascending loop of henle is impermeable to what?
water
what is abs in the distal tubule and what is secreted
reabsorbed: Na, Ca
secreted: K+, H+, HCO3-
which hormone can act on distal tubule and what does it do?
aldosterone…which stim formation of men proteins that will absorb sodium and secrete potassium
what does the distal tubule empty into
collecting duct- which is impermeable to water- but sensitive to ADH …it will inc perm of cells to the water so when ADH present, water will flow from tubule and concentrate filtrate
what does the juxtaglomerular apparatus do?
monitors filtrate pressure in the distal tubule. granular cells in the juxtaglomerular process secrete renin
what does renin do
renin starts a cascade to make angiotensin 1, 2 ,3 which ultimately stimulate adrenal cortex to secrete aldosterone. – which will form men proteins that will abs Na and secrete K
