Nerve: A bundle of fibers that uses electrical and chemical signals to transmit sensory and motor information from one body part to another. The fibrous portions of a nerve are covered by a sheath called myelin and/or a membrane called neurilemma.
The nervous system is a complex collection of nerves and specialized cells known as neurons that transmit signals between different parts of the body. Vertebrate animals with backbones and spinal columns have central and peripheral nervous systems.
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