The size of filtration slits of glomerulus

Options

A. 25 nm
B. 20 nm
C. 15 nm
D. 10 nm

Answer

### Step-by-Step Solution:

1. **Understanding the Glomerulus**:
- The glomerulus is a network of capillaries located in the Bowman's capsule of the nephron in the kidney. It plays a crucial role in the filtration of blood to form urine.

2. **Blood Flow into the Glomerulus**:
- Blood enters the glomerulus through the afferent arteriole, which branches from the renal artery. This blood is then subjected to filtration.

3. **Filtration Slits**:
- The filtration process occurs through specialized structures called filtration slits, which are formed by podocytes (cells with foot-like extensions) that wrap around the capillaries of the glomerulus.

4. **Size of Filtration Slits**:
- The size of these filtration slits is approximately 20 to 30 nanometers (nm). On average, the size is often cited as 25 nm.

5. **Function of Filtration Slits**:
- These slits allow small molecules such as water, glucose, and electrolytes to pass into the filtrate while preventing larger molecules like proteins and blood cells from entering.

6. **Conclusion**:
- Therefore, the size of the filtration slits of the glomerulus is approximately 25 nm.

### Final Answer:
The size of the filtration slits of the glomerulus is approximately **25 nm**.

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