A patient presents with severe dehydration. Which of the following physiological responses would be expected to occur in the kidney to conserve water?

The correct answer to the question "A patient presents with severe dehydration. Which of the following physiological responses would be expected to occur in the kidney to conserve water?" is Option D: Increased release of Antidiuretic Hormone (ADH).

The other options — A) Increased release of Atrial Natriuretic Peptide (ANP), B) Decreased collecting duct permeability to water, C) Increased reabsorption of sodium in the thick ascending limb — are incorrect for this USMLE Exam Prep question. As explained above: Severe dehydration increases plasma osmolarity, stimulating the release of ADH. ADH increases water reabsorption in the collecting ducts by increasing their permeability to water via aquaporin channe…