Question

Assertion :In the descending limb of loop of Henle, the urine is hypertonic, while is ascending limb of loop of Henle, the urine is hypotonic Reason: Descending limb is impermeable to $N{a}^{+}$,while ascending limb is impermeable to $H_{2}O$.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

The loop of Henle is a long U-shaped portion of the tubule that conducts urine within each nephron of the kidney. The main function of the loop of henle is the recovery of water and sodium chloride from the urine.

The descending limb is permeable to water, and the liquid reaching the bend of the loop is much richer than the blood plasma in salt and urea. As the liquid returns through the ascending limb, sodium chloride diffuses out of the tubule into the surrounding tissue, where its concentration is lower. The ascending limb of Henle's loop is impermeable to water.

So the answer is 'Both Assertion and Reason are correct and Reason is the correct explanation for Assertion'.