Which glial cell forms myelin in the peripheral nervous system?

Which glial cell forms myelin in the peripheral nervous system?

• A. Astrocytes
• B. Schwann cells
• C. Oligodendrocytes
• D. Microglia

Answer: (B)

In the peripheral nervous system, myelin is produced by Schwann cells. They wrap around a single axon segment to form a myelin sheath with gaps between adjacent Schwann cells, creating insulation that speeds nerve impulses through saltatory conduction. In contrast, oligodendrocytes handle myelination in the central nervous system, each cell extending processes to insulate multiple axons. Astrocytes support neuronal function and the blood–brain barrier, while microglia act as immune cells in the CNS, not myelin-forming cells. Schwann cells also aid peripheral nerve repair after injury.

In the peripheral nervous system, myelin is produced by Schwann cells. They wrap around a single axon segment to form a myelin sheath with gaps between adjacent Schwann cells, creating insulation that speeds nerve impulses through saltatory conduction. In contrast, oligodendrocytes handle myelination in the central nervous system, each cell extending processes to insulate multiple axons. Astrocytes support neuronal function and the blood–brain barrier, while microglia act as immune cells in the CNS, not myelin-forming cells. Schwann cells also aid peripheral nerve repair after injury.