- Describe the structure and functions of the neuron.
- Draw a diagram of the pathways of communication within and between neurons.
- List three of the major neurotransmitters and describe their functions.
The nervous system is composed of more than 100 billion cells known as neurons. A neuron is a cell in the nervous system whose function it is to receive and transmit information. As you can see in Figure 3.2 “Components of the Neuron”, neurons are made up of three major parts: a cell body, or soma, which contains the nucleus of the cell and keeps the cell alive; a branching treelike fiber known as the dendrite, which collects information from other cells and sends the information to the soma; and a long, segmented fiber known as the axon, which transmits information away from the cell body toward other neurons or to the muscles and glands.