what does a neuron consist of?
The brain sends messages through the spinal cord and nerves of the peripheral nervous system to control the movement of the muscles and the function of internal organs. The basic working unit of the nervous system is a cell called a neuron. The human brain contains about 100 billion neurons. A neuron consists of a cell body containing the nucleus, and special extensions called axons (pronounced AK-sonz) and dendrites (pronounced DEN-drahytz).