myelin sheath
Schwann cell myelin sheath
narrow
astrocyte sheath
narrow
oligodendrocyte myelin sheath
narrow
An electrically insulating fatty layer that surrounds the axons of many neurons. It is an outgrowth of glial cells: Schwann cells supply the myelin for peripheral neurons while oligodendrocytes supply it to those of the central nervous system.
GO:0110165
cellular anatomical structure
is_a