Glomerular capillaries exhibit higher pressure than that in other body capillary bed because

Options

A. There are two sets of capillaries in the kidney
B. Afferent arterioles are major site of autoregulatory resistance
C. Efferent arterioles have relatively high resistance
D. All of the above

Answer

**Step-by-Step Solution:**

1. **Understanding the Structure of Nephrons:**
- Nephrons are the structural and functional units of the kidney. Each nephron contains a glomerulus, which is a network of capillaries, and a Bowman's capsule that surrounds it.

2. **Blood Flow in Nephrons:**
- Blood enters the glomerulus through the afferent arteriole and exits through the efferent arteriole. The afferent arteriole brings blood into the glomerulus, while the efferent arteriole carries blood away from it.

3. **Diameter of Afferent and Efferent Arterioles:**
- The afferent arteriole has a larger diameter compared to the efferent arteriole, which has a smaller diameter. This difference in diameter is crucial for the pressure dynamics within the glomerulus.

4. **Resistance to Blood Flow:**
- The efferent arteriole provides higher resistance to blood flow due to its smaller diameter. This resistance causes an increase in pressure within the glomerular capillaries.

5. **Resulting Pressure in Glomerular Capillaries:**
- Because the efferent arteriole has high resistance, the pressure in the glomerular capillaries is higher compared to other body capillary beds. This higher pressure is essential for the filtration process that occurs in the kidneys.

6. **Conclusion:**
- Therefore, the reason glomerular capillaries exhibit higher pressure than other body capillary beds is that the efferent arteriole has relatively high resistance, leading to increased pressure in the glomerulus.

**Final Answer:**
Glomerular capillaries exhibit higher pressure than that in other body capillary beds because the efferent arteriole has relatively high resistance.

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