Neuron myelin segment

In this illustration of a neuron with a myelinated axon, a single segment of myelin is illustrated in green. Myelin is not part of the neuron itself. It is made up of membrane from a glial cell wrapped around the axon multiple times. In the central nervous system, myelin is formed from processes of oligodendrocytes, and one oligodendrocyte may provide myelin segments for multiple axons. In the peripheral nervous system, myelin is formed by Schwann cells, and each Schwann cell creates a segment of myelin for a single axon.