what part of the neuron is covered in myelin sheath

The part of the neuron that is covered in the myelin sheath is the axon. The myelin sheath is a fatty, insulating layer that wraps around the axon of many neurons. It is produced by glial cells: oligodendrocytes in the central nervous system (CNS) and Schwann cells in the peripheral nervous system (PNS). The myelin sheath serves several important functions:

Insulation: It insulates the axon, preventing electrical impulses from leaking out and ensuring they travel efficiently along the nerve fiber.