Urea
A) reabsorption occurs passively in the distal tubules
B) is only 50% reabsorbed in the proximal tubule.
C) is not normally found in the urine because it is completely reabsorbed
D) reabsorption is controlled by aldosterone
E) has a clearance value of 0

Question

Quizplus · Accepted Answer

Urea is about 50% reabsorbed in the proximal tubule by both passive and active mechanisms. It continues to be reabsorbed passively in the distal tubules but can also be secreted back into the tubules if necessary. Therefore, it is still present in small quantities in the urine. Urea reabsorption is not controlled by aldosterone. Clearance value for urea is not zero; it is typically used as an indicator of renal function.