Which of the following does not contribute to the establishment of a vertical osmotic gradient in the interstitial fluid of the renal medulla?
A) the renin-angiotensin-aldosterone system
B) countercurrent multiplication in the long loops of Henle of juxtamedullary nephrons
C) urea recycling between the late portion of the collecting tubule and the long loops of Henle
D) all of these
E) none of these

Question

Quizplus · Accepted Answer

The renin-angiotensin-aldosterone system primarily regulates blood pressure and electrolyte balance, and does not directly play a role in establishing the vertical osmotic gradient in the renal medulla. The other options (B and C) both contribute to the establishment of the gradient.

Which of the Following Does Not Contribute to the Establishment