Which glial cell forms myelin in the peripheral nervous system and each axon segment is myelinated by a single cell?

Which glial cell forms myelin in the peripheral nervous system and each axon segment is myelinated by a single cell?

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

Answer: (C)

Schwann cells are the glial cells responsible for forming myelin in the peripheral nervous system. They wrap around a single segment of an axon to create a myelin sheath, so each distinct axon segment is myelinated by its own Schwann cell. Along the same axon, many Schwann cells line up to produce successive myelin segments with gaps between them called nodes of Ranvier. This one‑to‑one relationship with myelination is what differentiates peripheral myelination from central myelination, where oligodendrocytes can extend processes to myelinate multiple segments. Astrocytes and microglia do not form myelin; astrocytes provide support and metabolic roles, and microglia act as immune cells in the nervous system.

Schwann cells are the glial cells responsible for forming myelin in the peripheral nervous system. They wrap around a single segment of an axon to create a myelin sheath, so each distinct axon segment is myelinated by its own Schwann cell. Along the same axon, many Schwann cells line up to produce successive myelin segments with gaps between them called nodes of Ranvier. This one‑to‑one relationship with myelination is what differentiates peripheral myelination from central myelination, where oligodendrocytes can extend processes to myelinate multiple segments. Astrocytes and microglia do not form myelin; astrocytes provide support and metabolic roles, and microglia act as immune cells in the nervous system.