The maximum amount of electrolytes and water (70-80 per cent) from the glomerular filtrate is reabsorbed in which part of the nephron?

Options

A. Distal convoluted tubule
B. Proximal convoluted tubule
C. Descending limb of loop of Henle
D. Ascending limb of loop of Henle

Answer

To determine where the maximum amount of electrolytes and water (70-80 percent) from the glomerular filtrate is reabsorbed in the nephron, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of the Nephron**:
- The nephron consists of several parts: the Bowman's capsule, proximal convoluted tubule (PCT), loop of Henle (which includes the descending and ascending limbs), distal convoluted tubule (DCT), and collecting ducts.

2. **Identify the Function of Each Part**:
- **Bowman's Capsule**: This is where filtration occurs, and it collects the glomerular filtrate.
- **Proximal Convoluted Tubule (PCT)**: This is primarily responsible for reabsorbing a significant amount of water, electrolytes, and nutrients from the filtrate back into the bloodstream.
- **Loop of Henle**: This structure plays a role in concentrating urine but does not reabsorb as much water and electrolytes as the PCT.
- **Distal Convoluted Tubule (DCT)**: This part also reabsorbs some water and electrolytes but to a lesser extent compared to the PCT.
- **Collecting Ducts**: These are involved in the final adjustments of water reabsorption but do not account for the majority of reabsorption.

3. **Focus on the Proximal Convoluted Tubule**:
- The PCT is known for its high capacity to reabsorb approximately 70-80% of the water and electrolytes from the glomerular filtrate. This is due to the presence of microvilli that increase the surface area for absorption and various transport proteins that facilitate the movement of substances.

4. **Conclude the Answer**:
- Based on the information gathered, the maximum amount of electrolytes and water (70-80 percent) from the glomerular filtrate is reabsorbed in the **Proximal Convoluted Tubule**.

### Final Answer:
The maximum amount of electrolytes and water (70-80 percent) from the glomerular filtrate is reabsorbed in the **Proximal Convoluted Tubule**.

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