Maximum water reabsorption occurs in

Options

A. DCT
B. PCT
C. Collecting duct
D. Descending limb of Henle

Answer

**Step-by-Step Solution:**

1. **Understanding the Nephron Structure:**
- The nephron is the functional unit of the kidney and consists of various parts including the Proximal Convoluted Tubule (PCT), Distal Convoluted Tubule (DCT), Loop of Henle, and Collecting Duct.

2. **Identifying Water Reabsorption Sites:**
- Water reabsorption occurs primarily in the nephron, particularly in the PCT, DCT, Loop of Henle, and Collecting Duct.

3. **Analyzing Each Part:**
- **Proximal Convoluted Tubule (PCT):** Responsible for reabsorbing about 70-80% of the filtered water, along with glucose and amino acids.
- **Distal Convoluted Tubule (DCT):** Involved in water reabsorption, but to a lesser extent compared to PCT. It mainly functions under specific conditions, such as low blood pressure.
- **Loop of Henle:** The descending limb is permeable to water, allowing some reabsorption but not as much as the PCT.
- **Collecting Duct:** Collects urine and can reabsorb water, but its primary function is not maximum reabsorption.

4. **Conclusion:**
- Based on the analysis, the PCT is the site of maximum water reabsorption in the nephron, making it the correct answer.

5. **Final Answer:**
- Maximum water reabsorption occurs in the **Proximal Convoluted Tubule (PCT)**.

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