renal q - jijibibi

[ArchivalUser]

RENAL

19. A 22-year-old woman is participating in a study that measures renal function. Evaluation of serum and urine shows the following:

Serum Urine
Na+ (mEq/L) 140 100
K+ (mEq/L) 4 50
Glucose (mg/dL) 100 0
Creatinine (mg/dL) 1 100
p-Aminohippuric acid (mg/mL) 0.1 50

Assuming a urine flow of 1 mL/min, which of the following best represents her filtration fraction?

A) .10
B) .20 ***
C) .30
D) .40
E) .50

[ArchivalUser]

b..

[ArchivalUser]

can u explain? I know b is the correct answe but have no idea how u get this number. thanks

[ArchivalUser]

hmmm
find out GFR first... GFR is in this case equals to creatinine clearance.. so that would be
Ucr*V/Pcr so thats 100*1/1
so GFR is 100

now find out renal plasma flow.. RPF. thats is equal to PAH clearance
Upah*V/Ppah so thats 50*1/.1
so rpf 500

FF = GRF/ RPF

100/500

u shd get it now if u dont i could elaborate further lemme know

[ArchivalUser]

Thanks a lot, cd45. You are excellent!