unmyelinated fiber


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unmyelinated fiber

(ŭn-mī′ə-lĭ-nā′tĭd)
n.
Any of the nerve fibers that lack a fatty myelin sheath but like other nerve fibers are enveloped by a sheath of Schwann cells.

unmyelinated fiber

A nerve fiber that lacks a myelin sheath, although a neurilemma may be present in the peripheral nervous system.
See also: fiber
References in periodicals archive ?
As noted, unmyelinated fibers compose the gray matter of the brain: as the number of myelinated fibers increase, the gray matter decreases and the white matter increases.
Unmyelinated fibers conduct very slowly (approximately 1 meter/second), while the speed of conduction in myelinated fibers depends on the total thickness of the fiber.
PHN is thought to be due to the destruction of the larger myelinated nerve fibers which are responsible for carrying inhibitory impulses, leaving out the smaller myelinated and unmyelinated fibers which are responsible for carrying nociceptive stimuli through the dorsal horn of spinal cord and hence pain is perceived.