The part of nephron involved in active reabsorption of sodium is
Answer: (B) Proximal convoluted tubule. Answer: (B) Proximal convoluted tubule (PCT).
- A.Distal convoluted tubule
- B.Proximal convoluted tubule✓
- C.Bowman's capsule
- D.Descending limb of Henle's loop
Correct Answer
(B) Proximal convoluted tubule
Solution & Explanation
Answer: (B) Proximal convoluted tubule (PCT). Solution: Reabsorption of Na+ (sodium) by active transport is a key function of the PCT, which is lined by a brush-border epithelium that increases surface area. The PCT reabsorbs nearly all essential nutrients and 70-80% of electrolytes and water. The descending/ascending limbs of Henle's loop and Bowman's capsule are not the primary site of active Na+ reabsorption. NCERT Reference: Ch 16, p.209, lines 28-31 — "Proximal Convoluted Tubule (PCT): PCT is lined by simple cuboidal brush border epithelium which increases the surface area for reabsorption. Nearly all of the essential nutrients, and 70-80 per cent of electrolytes and water are reabsorbed by this segment."