Question

The overall purpose of the countercurrent exchange system is to __________.

a. supply nutrients and oxygen to the renal medulla
b. supply salt and urea to the renal medulla
c. remove metabolic wastes from the renal cortex
d. supply nutrients and oxygen to the renal cortex
e. remove metabolic wastes from the renal medulla

Answer 1

The overall purpose of the countercurrent exchange system is to supply salt and urea to the renal medulla. This system creates a concentration gradient and a high osmolar environment in the depths of the medulla.

Step-by-step explanation:

The overall purpose of the countercurrent exchange system is to supply salt and urea to the renal medulla.

The countercurrent exchange system involves the descending and ascending loops of Henle directing forming urine in opposing directions to create a concentration gradient. This system is important for the recovery of NaCl (salt) to the circulation via the vasa recta and the creation of a high osmolar environment in the depths of the medulla. Collecting ducts also actively pump urea into the interstitial spaces, contributing to the high osmotic environment.