Antidiuretic hormone A) increases the permeability of the collecting ducts to water by increasing the number of aquaporins. B) is secreted in response to low potassium ion in the blood. C) causes the kidneys to produce a larger volume of very dilute urine. D) increases the permeability of the collecting ducts to water by decreasing the number of aquaporins. E) release is insensitive to the osmolarity of interstitial fluid.

A) increases the permeability of the collecting ducts to water by increasing the number of aquaporins.

Explanation:

ADH is an hormone of the anterior pituitary gland concern with osmoregualtion. When the solute potential of the blood rises, with decrease in water potential, the water levels of the blood drops, the osmoreceptors in the hypothalamus sensed this from the circulatory blood and prompted the hypothalamus to stimulate the anterior pituitary gland to secrete ADH.

The hormone is carried in the circulating blood to the walls of the collecting ducts where it binds with the receptors on the walls of the tubule, which increases the fusing and binding of Aquaporins to the membrane of the collecting ducts to increase re absorption of water back into the blood, raising the water potential of the blood.

The correct answer is option A) "increases the permeability of the collecting ducts to water by increasing the number of aquaporins".

Explanation:

Antidiuretic hormone, also known as Vasopressin, is a molecular messenger that stimulates water reabsorption in the kidneys. Antidiuretic hormone produce their effect by stimulating the synthesis and insertion of "water channels", known as aquaporins, into the membranes of the collecting tubules of the kidney. This increased number of aquaporins increases the permeability of the collecting ducts, which results in a greater water reabsorption in the kidneys.