Which one is impermeable to reabsorption of electrolytes in nephron?

Options

A. proximal convoluted tubule
B. distal convoluted tubule
C. ascending limb of loop of Henle
D. descending limb of loop of Henle

Answer

To determine which part of the nephron is impermeable to the reabsorption of electrolytes, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Nephron Structure**: The nephron is the functional unit of the kidney, consisting of several parts including the proximal convoluted tubule (PCT), loop of Henle (which has descending and ascending limbs), distal convoluted tubule (DCT), and collecting duct.

2. **Identify the Role of Each Part**:
- **Proximal Convoluted Tubule (PCT)**: This part is responsible for the reabsorption of a significant amount of water, electrolytes (like sodium and potassium), and nutrients. Therefore, it is not impermeable to electrolytes.
- **Loop of Henle**: This consists of two limbs:
- **Descending Limb**: Primarily permeable to water but not to electrolytes. It does not reabsorb electrolytes.
- **Ascending Limb**: This part is impermeable to water but actively reabsorbs electrolytes (like sodium and chloride).
- **Distal Convoluted Tubule (DCT)**: This part can reabsorb some water and electrolytes, but it is not the primary site for electrolyte reabsorption.

3. **Determine the Correct Answer**: Since the question asks for the part that is impermeable to the reabsorption of electrolytes, we note that the **descending limb of the loop of Henle** is the correct answer because it only allows the reabsorption of water and does not reabsorb electrolytes.

### Final Answer:
The descending limb of the loop of Henle is impermeable to the reabsorption of electrolytes.

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