Question

Which of the following hormones plays a key role in kidney osmoregulation by promoting water reabsorption in the collecting ducts?

• A. Insulin.
• B. Glucagon.
• C. Antidiuretic hormone (ADH).
• D. Aldosterone.

Hint:

ADH regulates water balance in the body by increasing water reabsorption in the collecting ducts, especially during dehydration or high blood osmolarity.

Answer 1

The Correct Option is C

Step 1: ADH's role in osmoregulation.
Antidiuretic hormone (ADH), or vasopressin, is secreted by the posterior pituitary. It enhances water reabsorption in the nephron's collecting ducts by increasing the permeability of the duct walls to water.

Step 2: Other hormones examined.
Insulin (Option A): Incorrect. Insulin manages glucose metabolism, not osmoregulation.

Glucagon (Option B): Incorrect. Glucagon elevates blood glucose and does not impact water reabsorption. 

Aldosterone (Option D): Incorrect. Aldosterone manages sodium and potassium balance, which indirectly influences water reabsorption, but it is not the primary osmoregulatory hormone. \[ \therefore \text{The key hormone for water reabsorption in the collecting ducts is: Antidiuretic hormone (ADH).} \]