The selective reabsorption of glucose and amon acids into the blood takes place mainly in :

Options

A. Proximal convoluted tubule
B. Henle's loop
C. Distal convoluted tubules
D. Collecting duct

Answer

To solve the question regarding where the selective reabsorption of glucose and amino acids into the blood takes place, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Structure of Nephrons**:
- Nephrons are the functional units of the kidneys, responsible for filtering blood and forming urine. Each nephron consists of a glomerulus and renal tubules.

2. **Identifying the Parts of the Nephron**:
- The nephron has several parts:
- **Glomerulus**: Responsible for filtration of blood.
- **Proximal Convoluted Tubule (PCT)**: The first segment of the renal tubule.
- **Loop of Henle**: The U-shaped segment that follows the PCT.
- **Distal Convoluted Tubule (DCT)**: The segment after the Loop of Henle.
- **Collecting Duct**: The final segment that collects urine from multiple nephrons.

3. **Function of Each Part**:
- **PCT**: Primarily responsible for the reabsorption of glucose, amino acids, and a significant portion of electrolytes and water.
- **Loop of Henle**: Mainly involved in the reabsorption of water and some ions.
- **DCT**: Involved in the conditional reabsorption of sodium ions, water, and bicarbonate ions.
- **Collecting Duct**: Plays a role in maintaining pH and secreting certain ions.

4. **Focusing on Glucose and Amino Acids**:
- The question specifically asks about the reabsorption of glucose and amino acids. The PCT is known to reabsorb approximately 70-80% of filtered glucose and amino acids back into the bloodstream.

5. **Conclusion**:
- Based on the functions of the nephron segments, the selective reabsorption of glucose and amino acids mainly occurs in the **Proximal Convoluted Tubule (PCT)**.

### Final Answer:
The selective reabsorption of glucose and amino acids into the blood takes place mainly in the **Proximal Convoluted Tubule (PCT)**.

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