Part of nephron impermeable to salt is

Options

A. descending limb of loop of Henle
B. ascending limb of loop of Henle
C. Distal convoluted tubule
D. collecting ducts

Answer

To answer the question "Part of nephron impermeable to salt is," we will analyze the structure and function of the nephron, particularly focusing on the loop of Henle.

### Step-by-Step Solution:

1. **Identify the Parts of the Nephron**:
The nephron consists of several parts, including the glomerulus, Bowman's capsule, proximal convoluted tubule, loop of Henle, distal convoluted tubule, and collecting duct.

2. **Focus on the Loop of Henle**:
The loop of Henle has two main segments: the descending limb and the ascending limb.

3. **Function of the Descending Limb**:
The descending limb of the loop of Henle is primarily permeable to water. It allows water to be reabsorbed back into the bloodstream, concentrating the urine.

4. **Function of the Ascending Limb**:
The ascending limb, on the other hand, is impermeable to water but is permeable to ions, particularly sodium (Na+) and chloride (Cl-). This segment actively reabsorbs these ions from the filtrate into the surrounding interstitial fluid.

5. **Determine Which Part is Impermeable to Salt**:
Since the ascending limb reabsorbs sodium and chloride ions (salt), it is not impermeable to salt. The descending limb does not reabsorb sodium and chloride ions, making it impermeable to salt.

6. **Conclusion**:
Therefore, the part of the nephron that is impermeable to salt is the **descending limb of the loop of Henle**.

### Final Answer:
The part of the nephron that is impermeable to salt is the **descending limb of the loop of Henle**.

---