CSF is not present in

Options

A. Ventricles of brain
B. Spinal cord (central canal )
C. Subdural space
D. Sub-arachnoid space

Answer

To solve the question "CSF is not present in," we need to analyze the options provided and understand where cerebrospinal fluid (CSF) is typically found.

### Step-by-Step Solution:

1. **Understanding CSF**:
- CSF stands for cerebrospinal fluid. It is a clear, colorless body fluid found in the brain and spinal cord. Its primary functions include cushioning the brain, providing buoyancy, and serving as a medium for nutrient transport.

2. **Analyzing the Options**:
- **Option 1: Ventricles of the brain**:
- CSF is produced in the ventricles of the brain. Therefore, CSF is present here.
- **Option 2: Spinal cord (central canal)**:
- CSF flows through the central canal of the spinal cord. Hence, CSF is present in the spinal cord as well.
- **Option 3: Subdural space**:
- The subdural space is located between the dura mater and the arachnoid mater. CSF is not present in this space; instead, it contains serous fluid. This is the correct answer to the question.
- **Option 4: Subarachnoid space**:
- The subarachnoid space is located between the arachnoid mater and the pia mater. CSF is present in this space.

3. **Conclusion**:
- Based on the analysis, the correct answer is **Option 3: Subdural space**, as CSF is not present there.

### Final Answer:
CSF is not present in the **subdural space**.