q2 - 2confused2bdoctor

[ArchivalUser]

An experiment is designed to determ. how much of plasma Na concen. is filtered into the tubule and subsenquently reabsorbed. Isolated pump-perfused rodent kidney preparation are constructed. Plasma Na is 135 mEQ/L and filtered load is found to be 15 mEQ/min. the predicted Na remain. in tubule at the end of descending limb of loop of henle is which of the follwing?
a)2 mEq/min
b)4 mEq/min
c)6 mEq/min
d)8 mEq/min
e)10 mEq/min

[ArchivalUser]

ee?

[ArchivalUser]

I guess i will explain..the answer is BBB. The filtered load for Na is plasma concen.. multiplied by GFR and is a measure of amt. of Na reaching the tubule. In this experiment, Na is reached the tubule at 15 mEq/min. The proximal tubule is respons. for about 70% of tubular Na reabsorp., and descending limb of loop of henle is impermeable to solutes. Therefore the amount of NA reaching the end of desc. limb of loop og henle is approx. 4 mEq/min
15 mEq/min x 0.70 = 11 mEq/min
15 mEq/min - 11 mEq/min = 4 mEq/min

[ArchivalUser]

thanks.....

[ArchivalUser]

hmm I am very bad in physio, thanks

[ArchivalUser]

thanks