Which of the following statements best describes the actions of the hormone ADH on the nephron?

• A. ADH increases the permeability of the collecting duct to water, leading to more concentrated urine.
• B. ADH enhances the filtration rate in the glomerulus.
• C. ADH decreases the reabsorption of sodium in the proximal convoluted tubule.
• D. ADH stimulates the secretion of potassium in the distal convoluted tubule.

Answer: (A)

Verified step by step guidance

1. Identify the primary function of the hormone ADH (Antidiuretic Hormone), which is to regulate water balance in the body by acting on the kidneys.
2. Understand that ADH primarily targets the collecting ducts of the nephron, which is the functional unit of the kidney.
3. Recognize that ADH increases the permeability of the collecting duct walls to water by promoting the insertion of water channels called aquaporins.
4. Realize that increased water reabsorption in the collecting ducts leads to more concentrated urine, as water is reabsorbed back into the bloodstream.
5. Conclude that the statement 'ADH increases the permeability of the collecting duct to water, leading to more concentrated urine' best describes the action of ADH on the nephron.