In Bowman's capsule

Options

A. afferent arteriole is narrower whereas efferent arteriole is wider
B. afferent arteriole is wider whereas efferent arteriole is narrow
C. afferent capillary is wider and efferent capillary is narrow
D. afferent capillary is narrow and efferent capillary is wide

Answer

### Step-by-Step Solution:

1. **Understanding the Structure**:
- The Bowman's capsule is a part of the nephron, which is the functional unit of the kidney. It is involved in the process of filtering blood to form urine.

2. **Identifying the Arterioles**:
- In the Bowman's capsule, there are two types of arterioles: the afferent arteriole and the efferent arteriole.
- The afferent arteriole brings blood into the glomerulus (a tuft of capillaries), while the efferent arteriole carries blood away from the glomerulus.

3. **Comparing Afferent and Efferent Arterioles**:
- The afferent arteriole is wider compared to the efferent arteriole. This difference in diameter is crucial for maintaining the pressure needed for filtration.
- The efferent arteriole is narrower, which helps to increase the pressure in the glomerulus, facilitating the filtration process.

4. **Understanding the Filtration Process**:
- Due to the high pressure created by the wider afferent arteriole and the narrower efferent arteriole, ultrafiltration occurs in the glomerulus. This process allows water, ions, and small molecules to pass into the Bowman's capsule, forming a filtrate.

5. **Conclusion**:
- Therefore, the correct statement regarding the arterioles is that the afferent arteriole is wider, and the efferent arteriole is narrower.

### Final Answer:
- The correct option is: **Afferent arteriole is wider, whereas efferent arteriole is narrower.**

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