MICROANATOMY

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: -The key difference between myelinated and unmyelinated nerve fibres is that the myelinated nerve fibres have myelin sheaths around them while the unmyelinated nerve fibres do not have the sheath.