Which cells are primarily responsible for myelination in the peripheral nervous system?

Which cells are primarily responsible for myelination in the peripheral nervous system?

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

Answer: (D)

In the peripheral nervous system, the cells that form the insulating myelin sheath around axons are Schwann cells. They wrap around a segment of a single axon, creating a myelin segment that speeds up nerve impulses through saltatory conduction, with signals leaping from one gap (the node of Ranvier) to the next. This rapid conduction is essential for quick motor responses and efficient peripheral signaling. Oligodendrocytes perform a similar insulation job in the central nervous system, but they can myelinate multiple axons at once. Astrocytes primarily support neurons and help regulate the extracellular environment, while microglia act as immune cells that clear debris and respond to injury in the CNS.

In the peripheral nervous system, the cells that form the insulating myelin sheath around axons are Schwann cells. They wrap around a segment of a single axon, creating a myelin segment that speeds up nerve impulses through saltatory conduction, with signals leaping from one gap (the node of Ranvier) to the next. This rapid conduction is essential for quick motor responses and efficient peripheral signaling.

Oligodendrocytes perform a similar insulation job in the central nervous system, but they can myelinate multiple axons at once. Astrocytes primarily support neurons and help regulate the extracellular environment, while microglia act as immune cells that clear debris and respond to injury in the CNS.