A neuron is a cell that transmit electrical signals. There are 3 types of neurons: motor, sensory and relay neuron. There are approximately 1011 neuron cells in the central nervous system of an individual. A typical neuron consists of a cell body, dendrites, axon and an axon terminal .
A neuron transmits electrical signals by action potentials. These are triggered when the cell receives a chemical signal, such as the one from Acetylcholine binding to the post synaptic membrane, causing Sodium voltage-gated ion channels to open and Sodium to diffuse down its concentration gradient into the neuron causing depolarisation (an electrical signal).
- ↑ Developmental Biology, 8th Edition, Scott F. Gilbert, Pg 394