Medullary Osmotic Gradient Flashcards
What creates an osmotic gradient within the renal medulla that allows for varying urine concentrations?
juxtamedullary nephrons
What part of the juxtamedullary nephrons create the gradient?
long nephron loops
What is the fxn of the long nephron loops of the juxtamedullary nephrons?
countercurrent multipliers
What preserves the osmotic gradient?
vasa recta
What is the function of the vasa recta?
countercurrent exchangers
What part of all nephrons use the gradient to adjust urine osmolality?
the collecting ducts
What is the osmolality of the medullary interstitial fluid in the deepest part of the medulla?
1200
T/F fluid entering the nephron loop is isosmotic to both blood plasma and cortical interstitial fluid
true
T/F filtrate is hyperosmotic to the interstitial fluid as it leaves the nephron loop
false, filtrate is hypo-osmotic. most dilute (100mOsm)
What determines the final concentration and volume of the urine?
the collecting ducts