Which of the following subtances is actively secreted into glomerular filtrate of the kidney tubule?

Options

A. Glucose
B. `H^(+)`
C. Amino acids
D. Chloride ions

Answer

To determine which substance is actively secreted into the glomerular filtrate of the kidney tubule, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Functions of the Nephron**:
- The nephron, the functional unit of the kidney, performs three main functions: ultrafiltration, selective reabsorption, and tubular secretion.

2. **Identify the Types of Substances**:
- The question provides four substances: glucose, H+ ions, amino acids, and chloride ions.

3. **Analyze Each Substance**:
- **Glucose**: This substance is primarily reabsorbed in the proximal convoluted tubule (PCT) and is not actively secreted.
- **H+ ions**: These ions are actively secreted into the tubular fluid from the blood in the PCT, distal convoluted tubule (DCT), and collecting duct.
- **Amino Acids**: Similar to glucose, amino acids are reabsorbed in the PCT and are not actively secreted.
- **Chloride Ions**: Chloride ions are also reabsorbed in the PCT and are not actively secreted.

4. **Determine the Correct Answer**:
- Based on the analysis, the only substance that is actively secreted into the glomerular filtrate is **H+ ions**.

5. **Conclusion**:
- The correct answer is **H+ ions**.

### Final Answer:
The substance that is actively secreted into the glomerular filtrate of the kidney tubule is **H+ ions**.

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