Which one of the following meninges is present only in mammalian brain

Options

A. Duramater
B. Arachnoid
C. Piamater
D. None of them

Answer

To solve the question "Which one of the following meninges is present only in the mammalian brain?", we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Meninges**: The meninges are protective membranes that cover the brain and spinal cord. There are three main layers of meninges: dura mater, arachnoid mater, and pia mater.

2. **Evaluate Each Option**:
- **Dura Mater**: This is the outermost layer of the meninges. It is thick and tough. Dura mater is present in all vertebrates, not just mammals. Therefore, this option is incorrect.

- **Arachnoid Mater**: This is the middle layer of the meninges. It is a web-like structure that is situated between the dura mater and pia mater. Importantly, the arachnoid mater is specifically noted for being present only in mammals. Thus, this option is correct.

- **Pia Mater**: This is the innermost layer of the meninges that closely adheres to the surface of the brain and spinal cord. Like the dura mater, pia mater is also present in all vertebrates, not just mammals. Therefore, this option is incorrect.

- **None of Them**: This option suggests that none of the previous options are correct. However, since we have established that the arachnoid mater is indeed present only in mammals, this option is also incorrect.

3. **Conclusion**: Based on the evaluation of the options, the correct answer to the question is the **Arachnoid Mater**, as it is the only layer of the meninges that is present exclusively in the mammalian brain.

### Final Answer:
The meninges that is present only in the mammalian brain is the **Arachnoid Mater**.

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