Sheaths of myelin produced by cells often enclose the axons outside of the brain and spinal cord.

Sheaths of myelin produced by SCHWANN cells often enclose axons outside of the brain and spinal cord. Schwann cells are the cells in the peripheral nervous system that are responsible for producing myelin sheath that occurs around the neuronal axon. These cells get their name from Theodor Schwann who discovered them.

The light is great source of energy