Question

Which of the following statements is correct regarding the loop of Henle?

• A. The ascending limb of the loop of Henle is impermeable to water
• B. The descending limb of the loop of Henle is impermeable to water
• C. The ascending limb of the loop of Henle permeable to water
• D. The descending limb of the loop of Henle is permeable to electrolytes

Answer 1

The correct option is A

The ascending limb of the loop of Henle is impermeable to water

The correct option is A.

Explanation of correct option:

1. While actively reabsorbing sodium chloride (NaCl), Henle's loop's thick ascending limb is impervious to water.
2. As a result, this segment increases the osmolality of the interstitial fluid, leading to medullary interstitial hypertonicity and an osmotic gradient from the lumen to the interstitium.
3. In the ascending limb, NaCl is pumped from the tubule into the interstitium.
4. As fluid exits the loop, tubular osmolarity declines and becomes hypotonic.

Explanation of incorrect options:

Option B:

1. The thin descendant limb of the Henle loop is highly permeable to water but less permeable to urea and ions.
2. Because water is reabsorbed together with ions via the gradient time system to maintain the fluid's osmolarity in the PCT, the fluid is isotonic.

Option C:

1. Henle's loop's thin, ascending limb is extremely water-impermeable and the descendant limb of the Henle loop is highly permeable to water.

Option D:

1. Henle's loop's descending limb is impermeable to electrolytes.
2. The potassium, sodium, and chloride ions from the urine are here reabsorbed into the body by the ascending limb of the Henle loop.

Final answer: The correct statement regarding Henle's loop is that the ascending limb of the loop of Henle is impermeable to water.