Which cell type produces myelin in the peripheral nervous system?

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

Answer: (B)

Myelin in the peripheral nervous system is produced by Schwann cells. These glial cells wrap themselves around a single axon segment, forming multiple layers of membrane to create the insulating sheath that speeds electrical conduction along the nerve. This is different from the central nervous system, where oligodendrocytes handle myelination, typically by extending processes to myelate portions of many axons. Astrocytes support neuronal function and maintain the extracellular environment, while microglia act as immune cells in the CNS. Thus, Schwann cells are the cells responsible for peripheral myelin.