Peripheral nerve myelin sheath

The peripheral nerve myelin sheath is a specialized, lipid-rich membrane produced by Schwann cells that spirally wraps around axons in the peripheral nervous system[2][7][9][5]. This sheath consists of up to hundreds of concentric layers, with each segment termed an internode and separated by nodes of Ranvier, where rapid signal “jumping” (saltatory conduction) takes place[7]. The membrane is composed mostly of lipids (70–80%) and proteins (20–30%), most notably myelin protein zero (P0), peripheral myelin protein 22 (PMP22), and myelin basic protein (MBP)[1][6][8]. The sheath insulates axons, enables rapid signal transmission, and helps maintain axon health and regeneration after injury[7][9]. Damage or genetic abnormalities in sheath components cause various peripheral neuropathies and inherited myelin disorders[3][6]. While the sheath itself is not a primary drug target, its failure is a crucial element in several neurological diseases.

Other names

Myelin sheath (in PNS context)Peripheral myelinSchwann cell myelin

Not applicable