Question

Descending loop of Henle is for

• A. Absorption of NH₃
• B. Absorption of Na⁺
• C. Release of urea
• D. Maintaining water balance

Answer 1

The correct option is D

Maintaining water balance

The correct option is : D

Explanation of the correct option :

1. The structure of kidney or nephron is comprised of glomerular apparatus, proximal convoluted tubule, Henle's loop and distal convoluted tubule.
2. Henle’s loop is mainly accountable for the reabsorption of salts and water, maintaining of water balance , concentration and volume of blood.
3. The filtrate entering into the Henle's loop is known as glomerular filtrate rich in sodium, potassium and other ions and water.
4. The descending loop of Henle's is permeable to water and the reabsorption takes place and thus, concentrates the filtrate as it moves down.
5. This region is impermeable to the salts or ions, whereas the ascending loop is impermeable to water and permeable t o salts or ions.
6. The filtrate at the base of loop is hypertonic.
7. The cell present in each tube absorbs different molecules excluding the glucose, water, and other beneficial molecules which are called as ultrafiltrate.
8. As the ultrafiltrate molecules travel down the tubules they become more and more hypertonic, which results in more amount of water to be extracted from the ultrafiltrate before it exits the nephrons.

Explanation of the incorrect option:

Option A:

Ascending limb of the nephron is responsible for absorption of NH_3.

Option B:

Absorption of sodium facilitates at the nearby sections of the distal tubule.

Option C:

Nephron filters the urea and other waste from the blood along with excess water and send to the urinary bladder through the ureter. Nephron does not release urea.

Final answer: Descending loop of Henle is for maintaining water balance.