Neuron - Definition

April 2017


Definition

Neurons are the primary cells of the nervous system, principally serving as messengers and sorters of information in the body. There are millions of neurons in our body, each consisting of a nucleus surrounded by thin structures fanning out, called dendrites, and a long extension that can measure 20 to 30 centimeters, called the axon. Some neurons play a role in the body's movements, some in sensory perception, and others are involved in the autonomic nervous system that controls involuntary functions. Put simply, motor neurons originating in the central nervous system relay commands via nerve impulses, which are passed on by intermediary neurons. The communication between one neuron and another is called a synapse, and consists of releasing a substance called a neurotransmitter that is detected by the receptors of the nearest neuron. Information can also be received and understood at the terminal end by what is called an effector cell, such as a muscle cell that will produce the "commanded" action. For sensory function, a stimulus (stimulating factor) induces an "excitatory" effect in a neuron, which then uses a mechanism similar to that of motor neurons to relay the message to the brain for interpretation.

Schema

Related

Original article published by . Translated by Jeff. Latest update on August 19, 2014 at 12:23 PM by christelle.b.
This document, titled "Neuron - Definition," is available under the Creative Commons license. Any copy, reuse, or modification of the content should be sufficiently credited to CCM Health (health.ccm.net).