What forms a myelin sheath?

The myelin sheath is formed by specialized glial cells in the nervous system. In the central nervous system (CNS), oligodendrocytes produce myelin, while in the peripheral nervous system (PNS), Schwann cells are responsible for its formation. These cells wrap around the axons of neurons in multiple layers, providing insulation that enhances the speed of electrical signal transmission. The myelin sheath is crucial for efficient communication between nerve cells.