Schwann cell

Named after the German physiologist Theodor Schwann, Schwann cells (also referred to as neurolemmocytes) are a variety of glial cell that mainly provide myelin insulation to axons in the peripheral nervous system of jawed vertebrates. The vertebrate nervous system relies on this myelin sheath for insulation and as a method of decreasing membrane capacitance in the axon, thus allowing for saltatory conduction to occur and for an increase in impulse speed, without an increase in axonal diameter. Non-myelinating Schwann cells are involved in maintenance of axons and are crucial for neuronal survival. Some group around smaller axons and form Remak bundles. Schwann cells are the peripheral nervous system's analogues of the central nervous system oligodendrocytes.
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Noun
1. any cell that covers the nerve fibers in the peripheral nervous system and forms the myelin sheath
(hypernym) somatic cell, vegetative cell

A type of glial cell of the peripheral nervous system that helps separate and insulate nerve cells.