Question

Which among the following statement(s) is/are true?
I. Descending limb of Henle’s loop is permeable to water.
II. Ascending limb of Henle’s loop is permeable to electrolytes.
III. Descending limb of Henle’s loop is permeable to electrolytes.
IV. Reabsorption is minimum in Henle’s ascending loop region.

• A. III is true
• B. I and IV are true
• C. I and III are true
• D. I, II and IV are true

Answer 1

The correct option is D I, II and IV are true

The renal tubule of nephron comprises Bowman’s capsule, proximal convoluted tubule, Henle’s loop, distal convoluted tubule and collecting duct.

Henle’s loop is a hairpin like structure with descending and ascending loops. Henle’s loop plays an important role in maintenance of high osmolarity of medullary interstitial fluid.
The descending limb of Henle’s loop is permeable to water but impermeable to electrolytes. This makes the filtrate concentrated as it moves down the Henle’s loop. The ascending limb is impermeable to water but permeable to electrolytes. Hence, the filtrate gets diluted as it passes the ascending loop region. Reabsorption is minimum in its ascending limb.