Control of volume Flashcards
Why do we not just add or remove water to change ECF?
It would change the osmolarity
Is sodium absorption mainly active or passive?
Active
Which part of the nephron does not absorb water?
Ascending limb of the Loop of Henle
Where is the Na/K ATPase on the epithelial cell?
Basolateral membrane
What substances are reabsorbed completely?
Glucose, AA and Lactate
What is reabsorbed in PCT s2-3?
Chloride ions paracellular or transcellular, and Na via Na/H transporter. Water paracellular
What type of epithelium lines the descending loop of henle?
squamous ( to absorb lots of water)
What does the thin ascending limp do?
Passive Na reabsorption (transcellular)
What does the thick ascending limb do?
Active Na reabsorption
Which channel does the loop diuretic furosemide inhibit?
NKCC2
What does the ROMK channel do?
Secretes K into the lumen so that it can be used for the NKCC2 channel
What happens in the DCT?
Active reabsorption of Na if necessary
What channel does Thiazides block and where?
Na/Cl transporters on the apical membrane of DCT
Which channel does Amiloride inhibit and where?
ENac, on the apical membrane of the late DCT
Where is calcium reabsorbed and what does it bind to?
DCT, Calbindin
