Question

Vasopressin quickly increases the reabsorption of water by the collecting duct. This happens because:

a) It inhibits ADH production
b) It dilates blood vessels
c) It stimulates aldosterone release
d) Preformed aquaporins are translocated to the membrane.

Answer 1

ADH release from the posterior pituitary causes vasoconstriction and activates aquaporin channels in the collecting ducts to increase water reabsorption.

Step-by-step explanation:

When blood volume drops 5-10 percent, causing a decrease in blood pressure, there is a rapid and significant increase in ADH release from the posterior pituitary. Immediate vasoconstriction to increase blood pressure is the result. ADH also causes activation of aquaporin channels in the collecting ducts to affect the recovery of water to help restore vascular volume.