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A 35-year-old man is referred to the renal clinic for evaluation of proteinuria. He has no complaints other than foamy urine. The following data are obtained from the patient:
Inulin clearance 100 mL/min
Plasma osmolarity 286 mOsm/L
Plasma sodium concentreation 140 mEq/L
Urine flow 1.44 l/ 24 hour
Urine osmolarity 205 mOsm/L
Urine sodium concentration 100 mEq/L
How much sodium does this patient reabsorb each day?
A. 14 mEq
B. 144 mEq
C. 244 mEq
D. 20,016 mEq
E. 20,160 mEq


Show your calculation. thanks

Of the Na filtered, 99-99.5% is norm reabsorbed ( 67% PCT, 25% Loop hen & 8% DCT)

^Na filtration: ( Plasma Na conc & GFR = inulin clearance)
140 mEq/L x 100 mL/min -> 20,160 mEq/ DAY

^^Na excreted: ( Urine Na conc & Urine flow)
100 mEq/L x 1.44 L / day - > 144 mEq/DAY

Na reabsorption = ^Filtered – ^^Excreted -> 20,160 mEq/DAY - 144 mEq/DAY -> 20,016mEq.

The End.

ohhh per "Day".....thats where i went wrong....thanks for the rescue as always!!!

thanks cardio