Physiology The ability of kidney to form a concentrated urine will decrease if: A The permeability of the collecting duct to water decreases B Rate of blood flow through the medulla increases C Activity of Na+/K+-pump in the loop of Henle decreases D Aquaporin inseion is suppressed. 💡 Explanation The ability of kidney to form a concentrated urine will decrease if: ✓ Correct Answer: B. Rate of blood flow through the medulla increases