Effective filtration pressure in glomerulus is maintained due to

Options

A. Powerful pumping action of the heart.
B. Secretion of adrenaline
C. afferent arteriole being slightly larger than efferent arteriole .
D. Vacuum develops in collecting duct and sucks the blood .

Answer

To determine the factor that maintains the effective filtration pressure in the glomerulus, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Glomerulus**:
- The glomerulus is a network of capillaries located within the nephron of the kidney. It plays a crucial role in the filtration of blood, separating waste from useful substances.

2. **Identifying the Components**:
- The glomerulus is surrounded by a cup-shaped structure called Bowman's capsule. Blood enters the glomerulus through the afferent arteriole and exits through the efferent arteriole.

3. **Role of Afferent and Efferent Arterioles**:
- The afferent arteriole has a larger diameter compared to the efferent arteriole. This difference in diameter is critical for maintaining effective filtration pressure.

4. **Mechanism of Filtration**:
- When blood enters the glomerulus through the afferent arteriole, the larger diameter allows a greater volume of blood to flow in. In contrast, the narrower efferent arteriole restricts the outflow of blood, leading to an increase in pressure within the glomerulus.

5. **Impact on Filtration Rate**:
- The increased pressure in the glomerulus enhances the filtration rate. The effective filtration pressure is the net pressure that promotes the movement of fluid from the blood into Bowman's capsule, facilitating the filtration process.

6. **Conclusion**:
- Therefore, the factor that maintains the effective filtration pressure in the glomerulus is primarily due to the afferent arteriole being slightly larger than the efferent arteriole. This anatomical difference is crucial for ensuring that more blood enters the glomerulus than exits, thereby increasing the filtration rate.

### Final Answer:
The effective filtration pressure in the glomerulus is maintained due to the afferent arteriole being slightly larger than the efferent arteriole.