Nerve

Article By:

Webster, Douglas B. Department of Otorhinolaryngology and Biocommunication, Louisiana State University Medical Center, Baton Rouge, Louisiana.

Last reviewed:July 2021

DOI:https://doi.org/10.1036/1097-8542.449200

A group of nerve fibers coursing together as a bundle in the peripheral nervous system. Nerves (see illustration), which are enclosed bundles of neurons (nerve cells), are significant structural components of the peripheral nervous system of vertebrates. Specifically, the nerves and ganglia (groups of nerve cell bodies) that leave the brain and spinal cord constitute the peripheral nervous system. Most importantly, nerves conduct electrical impulses that relay information from one part of the body to another. Individual nerve fibers are covered by Schwann cells. Many of these cells contain large amounts of protective myelin, making nerves appear shiny white. The nerve fibers with their Schwann cell sheaths are held together by connective tissue. In most nerves, some fibers are sensory (carrying information to the central nervous system) and some fibers are motor (carrying information from the central nervous system to peripheral glands and muscles). When both sensory and motor fibers appear in a nerve, it is called a mixed nerve. See also: Brain; Central nervous system; Connective tissue; Ganglion; Motor systems (neuroscience); Nervous system (vertebrate); Neurobiology; Neuron; Spinal cord

The content above is only an excerpt.