Question

Which of the following best describes the direct effect of vasopressin?

A.) increases water reabsorption at the collecting duct of the kidney
B.) decreases blood plasma osmolarity
C.) decreases water reabsorption at the collecting duct of the kidney
D.) increased blood plasma osmolarity

Answer 1

The direct effect of vasopressin (ADH) is to increase water reabsorption at the collecting duct of the kidney by moving aquaporins to the cell surface, enhancing water passage from urine to the bloodstream.

Step-by-step explanation:

The direct effect of vasopressin, which is also known as antidiuretic hormone (ADH), best describes increases water reabsorption at the collecting duct of the kidney. Vasopressin does so by causing the epithelial cells lining the renal collecting tubules to move water channel proteins, aquaporins, to their apical surface, which increases the permeability of these cells to water. As a result, there is enhanced water passage from the urine through the walls of the collecting tubules, allowing more water to be reabsorbed into the bloodstream.