The glomerular afferent arteriole has a pressure of

Options

A. `+ 120 mm Hg`
B. `-120 mm Hg`
C. `+95 mm Hg`
D. `+75 mm Hg`

Answer

To solve the question regarding the pressure in the glomerular afferent arteriole, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for the pressure in the glomerular afferent arteriole. This is a key component of the renal system involved in filtering blood.

2. **Identify the Options**: The options provided are:
- +120 mm Hg
- -120 mm Hg
- +95 mm Hg
- +75 mm Hg

3. **Recall Relevant Information**: The normal pressure in the glomerular afferent arteriole is approximately 75 mm Hg. This pressure is crucial for the filtration process in the kidneys.

4. **Consider Opposing Pressures**: It is important to note that this pressure is opposed by:
- Osmotic pressure (approximately 30 mm Hg)
- Hydrostatic pressure (approximately 20 mm Hg)

5. **Evaluate Each Option**:
- **+120 mm Hg**: This is too high and incorrect.
- **-120 mm Hg**: Negative pressure is not applicable here and is incorrect.
- **+95 mm Hg**: This is also too high and incorrect.
- **+75 mm Hg**: This matches the known pressure in the glomerular afferent arteriole and is correct.

6. **Conclusion**: The correct answer is +75 mm Hg.

### Final Answer:
The glomerular afferent arteriole has a pressure of **+75 mm Hg**.

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