Summary:
- The nervous system is a complex network of nervous tissue that carries electrical messages throughout the body.
- Neurons are the structural and functional units of the nervous system.
- They transmit electrical signals, called nerve impulses.
- Glial cells provide support for neurons by providing nutrients and other materials.
- The axon of many neurons has an outer layer called a myelin sheath.
- Myelin is a lipid produced by a type of a glial cell known as a Schwann cell.
- It acts like a layer of insulation, similar to the plastic that encases an electrical cord.