MRCP UK EXAMINATIONS

Detailed explanation-1: -Myelinated fibers make up the white matter in the CNS, while cell bodies and unmyelinated fibers make the gray matter. The unmyelinated regions between the myelin segments are called the nodes of Ranvier. In the peripheral nervous system, the myelin is produced by Schwann cells.

Detailed explanation-2: -Myelin gives the white matter its color. It also protects the nerve fibers from injury. Also, it improves the speed and transmission of electrical nerve signals along extensions of the nerve cells called axons. By comparison, gray matter is tissue found on the surface of the brain (cortical).

Detailed explanation-3: -In the central nervous system, myelinated fibres form the white matter.

Detailed explanation-4: -Myelinated neurons have nerve fibres that are covered by a myelin sheath and are present in the white matter of the nervous system. On the other hand, non-myelinated nerve fibres do not have myelin sheath and are present in the grey matter of the nervous system.