7.2 Physiology of the Urinary System Part 4 Flashcards
What is involved in countercurrent flow?
vasa recta
peritubular capillaries
filtrate through the loop of henle
What is countercurrent flow?
movement of fluids in opposite direction through adjacent channels
What is the general description of countercurrent flow in the kidneys?
filtrate flows one direction through the renal tubules while blood flows in the opposite direction
What is the osmotic gradient?
concentration of solutes inside of a solution
What is osmotic gradient measured in?
mOsm / L
What helps protect the osmotic gradient in the medullary interstitial space?
capillaries
What is isosmotic?
when the fluid inside and outside have the same osmotic concentrations
Where is there isosmotic concentration in the kidney?
filtrate entering the PCT
How does the osmotic concentrations change in the descending limb o f the loop of Henle?
solute concentration increases as it desends
What is the actual measurement of the osmotic concentrations at the beginning of the PCT?
300 mOsm/L
What is the actual measurement of the osmotic concentrations at the hairpin turn of the loop of Henle?
1200 mOsm/l
Why does the osmotic concentrations increases at the hair pin turn of the loop of Henle?
water can leave but solutes cannot
What is the osmotic concentrations after the ascending limb o the loop of Henle?
100 mOsm/L
Why does the osmotic concentrations decrease after the ascending limb of the loop of Henle?
solute can leave but water cannot
What is urea?
substance that is converted from ammonia to be excreted in urine
