Renal physiology Flashcards
What does isosmotic resorption mean?
Same osmotic pressure at the beginning and the end of the tubule
Where along the nephron would you expect to find isosmotic absorption?
PCT
What are the major cations included in the general term solute in the PCT?
Na
K
H
What are the major accompanying anions included in the general term solute in the PCT?
HCO3- in the early part of the PCT
Cl- in the late part of the PCT
On which membrane is NaK-ATPase located in the PCT?
Basolateral membrane
What are the primary driving forces for the movement of solute and solvent into the peritubular capillaries?
Intracellular space: hydrostatic pressure
Peritubular blood: oncotic and osmotic pressure
What is the function of tight junctions?
Helps to maintain the polarity of the cell.
What histological features of the epithelial cells lining the descending limb of the loop of Henle indicate that they are not involved in active transport?
Gap junctions
Aquaporin
What is passively reabsorbed in the descending limb of the loop of Henle?
Water
Which transport proteins are on the apical membrane of the ascending limb of the loop of Henle?
NaKCC2.
Sodium-Potassium-2Chlorine.
ROMK (passive movement of K+ out of the cell)
Why is the movement of K+ back into the lumen vital to continued activity of NaKCC2?
Prevents extracellular concentration of K+ falling too low to keep NaKCC2 functioning.
What percentage of Na ions does the DCT reabsorb?
5%
