Nerves of the left upper extremity.gif
Nerves (yellow) in the arm
SystemNervous system
Anatomical terms of neuroanatomy

A nerve is an enclosed, cable-like bundle of nerve fibers (called axons) in the peripheral nervous system.

Axons transmit electrical impulses. Nerves have historically been considered the basic units of the peripheral nervous system. A nerve provides a common pathway for the electrochemical nerve impulses called action potentials that are transmitted along each of the axons to peripheral organs or, in the case of sensory nerves, from the periphery back to the central nervous system. Each axon, within the nerve, is an extension of an individual neuron, along with other supportive cells such as some Schwann cells that coat the axons in myelin.

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nerve cell and organization

Within a nerve, each axon is surrounded by a layer of connective tissue called the endoneurium. The axons are bundled together into groups called fascicles, and each fascicle is wrapped in a layer of connective tissue called the perineurium. Finally, the entire nerve is wrapped in a layer of connective tissue called the epineurium. Nerve cells (often called neurons) are further classified as sensory, motor, or mixed nerves.

In the central nervous system, the analogous structures are known as nerve tracts.[1][2]

  1. ^ Cite error: The named reference Purves was invoked but never defined (see the help page).
  2. ^ Marieb EN, Hoehn K (2007). Human Anatomy & Physiology (7th ed.). Pearson. pp. 388–602. ISBN 978-0-8053-5909-1.

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