ANATOMY

Detailed explanation-1: -Schwann cells make myelin in the peripheral nervous system (PNS: nerves) and oligodendrocytes in the central nervous system (CNS: brain and spinal cord). In the PNS, one Schwann cell forms a single myelin sheath (Figure 1A).

Detailed explanation-2: -CNS myelin is produced by special cells called oligodendrocytes. PNS myelin is produced by Schwann cells. The two types of myelin are chemically different, but they both perform the same function-to promote efficient transmission of a nerve impulse along the axon.

Detailed explanation-3: -They form as the result of reciprocal interactions between axons and Schwann cells. Extrinsic signals from the axon, and the extracellular matrix, drive Schwann cells to adopt a myelinating fate, whereas myelination reorganizes the axon for its role in conduction and is essential for its integrity.

Detailed explanation-4: -Schwann cells are a variety of glial cells that keep peripheral nerve fibres (both myelinated and unmyelinated) alive. In myelinated axons, Schwann cells form the myelin sheath.