NEURON encyclopedia topics

NEURON - 4 reference results

neuron, specialized cell in animals that, as a unit of the nervous system, carries information by receiving and transmitting electrical impulses.

The Columbia Electronic Encyclopedia Copyright © 2004.
Licensed from Columbia University Press

motor neuron disease

motor neuron disease: see amyotrophic lateral sclerosis.

The Columbia Electronic Encyclopedia Copyright © 2004.
Licensed from Columbia University Press

neuron

or nerve cell

Structure of a neuron. Dendrites, usually branching fibres, receive and conduct impulses to the elipsis

Any of the cells of the nervous system. Sensory neurons relay information from sense organs, motor neurons carry impulses to muscles and glands, and interneurons transmit impulses between sensory and motor neurons. A typical neuron consists of dendrites (fibres that receive stimuli and conduct them inward), a cell body (a nucleated body that receives input from dendrites), and an axon (a fibre that conducts the nerve impulse from the cell body outward to the axon terminals). Both axons and dendrites may be referred to as nerve fibres. Impulses are relayed by neurotransmitter chemicals released by the axon terminals across the synapses (junctions between neurons or between a neuron and an effector cell, such as a muscle cell) or, in some cases, pass directly from one neuron to the next. Large axons are insulated by a myelin sheath formed by fatty cells called Schwann cells. Bundles of fibres from neurons held together by connective tissue form nerves.

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Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.