Opaque white appearance of white matter is due to :-

Options

A. Fibers of tract covered by axolemma only
B. Fibers of tract not covered by myelin sheath
C. Fibers of tract covered by myelin sheath
D. White matter absent in CNS

Answer

To solve the question regarding the opaque white appearance of white matter, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of the Nervous System**:
- The nervous system is composed of gray matter and white matter. Gray matter consists of neuronal cell bodies, while white matter consists of myelinated axons.

2. **Identify the Components of White Matter**:
- White matter is primarily made up of myelinated axons. The myelin sheath is a fatty layer that surrounds the axons of many neurons.

3. **Recognize the Role of Myelin**:
- Myelin serves to insulate the axons, allowing for faster transmission of electrical signals between neurons. The presence of myelin gives the white matter its characteristic appearance.

4. **Analyze the Options Provided**:
- Option A: Fibers of tract covered by auxilima only - This is incorrect as auxilima is not a relevant term in this context.
- Option B: Fibers of tract not covered by myelin sheath - This would not give a white appearance, as unmyelinated fibers are typically gray.
- Option C: Fibers of tract covered by myelin sheath - This is correct, as the myelin sheath gives the white matter its opaque white appearance.
- Option D: White matter absent in CNS - This is incorrect, as white matter is present in the central nervous system (CNS).

5. **Conclude the Correct Answer**:
- Based on the analysis, the correct answer is **Option C: Fibers of tract covered by myelin sheath**.

### Final Answer:
The opaque white appearance of white matter is due to **fibers of tract covered by myelin sheath**.

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