Which of the following is not a feature of the cortical nephron?

Options

A. Vasa recta are absent
B. Shorter loop of Henle
C. Fewer in number
D. Slower rate of filtration

Answer

To solve the question "Which of the following is not a feature of the cortical nephron?", we will analyze the characteristics of cortical nephrons and compare them with the options provided.

### Step-by-Step Solution:

1. **Understanding Nephrons**:
- Nephrons are the functional units of the kidney, and they can be classified into two types: cortical nephrons and juxtamedullary nephrons.
- Cortical nephrons are primarily located in the renal cortex, while juxtamedullary nephrons extend into the medulla.

2. **Identifying Features of Cortical Nephrons**:
- **Vasa Recta**: This refers to the straight capillaries that supply blood to the nephron. Vasa recta are primarily associated with juxtamedullary nephrons, not cortical nephrons. Therefore, this is a feature that is NOT present in cortical nephrons.
- **Loop of Henle**: Cortical nephrons have a shorter loop of Henle compared to juxtamedullary nephrons, which have a longer loop that extends deeper into the medulla.
- **Number of Nephrons**: Cortical nephrons make up about 80% of the total nephron population in the kidney, while juxtamedullary nephrons account for about 20%. Thus, cortical nephrons are more numerous.
- **Rate of Filtration**: The filtration rate in cortical nephrons is generally slower compared to juxtamedullary nephrons due to their structure and location.

3. **Analyzing the Options**:
- Based on the features discussed:
- A) Vasa Recta - Not a feature of cortical nephron.
- B) Shorter Loop of Henle - A feature of cortical nephron.
- C) Fewer in Number - Incorrect, as cortical nephrons are more numerous.
- D) Slower Rate of Filtration - A feature of cortical nephron.

4. **Conclusion**:
- The option that is NOT a feature of the cortical nephron is **C) Fewer in Number**. Cortical nephrons are actually more numerous than juxtamedullary nephrons.

### Final Answer:
C) Fewer in Number