NeuroN

The basic cells of the nervous systems of animals, whose job is to transmit and process signals. Neurons occur both in nerves and the brain. The former are mostly for bringing sensory information in and controlling bodily functions; sometimes nerves are hooked up to elicit a response on their own, called a reflex, but more often reactions are decided in the brain.

An individual neuron has a sort-of-amoeboid cell body, from which extends a long (potentially several metres) projection called the axon, and numerous shorter protoplasmic branches called dendrites. Hormones called neurotransmitters are received on the dendrites and affect the voltage of the cell, normally around -50 mV thanks to the ion pump. When it reaches a certain threshold level, there is a dramatic change in the ion pump that causes a electric pulse to travel along the axon. When it reaches the terminals there, it stimulates them to release other neurotransmitters, which are either applied to another neuron or to some kind of muscle.