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

**Step-by-Step Solution:**

1. **Understanding White Matter**: White matter is a component of the central nervous system (CNS) and peripheral nervous system (PNS). It primarily consists of myelinated axons, which are nerve fibers covered by a myelin sheath.

2. **Role of Myelin Sheath**: The myelin sheath is a fatty layer that surrounds the axons of many neurons. This sheath is crucial for the proper functioning of the nervous system as it facilitates faster transmission of electrical signals along the nerve fibers.

3. **Color of Myelin Sheath**: The myelin sheath has a white appearance due to its lipid (fat) content. This lipid-rich composition is what gives the white matter its characteristic opaque white color.

4. **Conclusion**: Therefore, the opaque white appearance of white matter is due to the presence of the myelin sheath covering the nerve fibers. This is the primary reason why white matter appears white.

5. **Final Answer**: The opaque white appearance of white matter is due to the presence of the myelin sheath covering the nerve fibers.

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