Term: brain myelin sheath
Name: brain
Synonyms: brain structure
Definition: Cavitated compound organ which is comprised of gray and white matter and surrounds the cerebral ventricular system.
Ontology: Anatomy Ontology [ZFA:0000008]

Name: myelin sheath
Synonyms: astrocyte sheath, oligodendrocyte myelin sheath, Schwann cell myelin sheath
Definition: 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.
Ontology: GO: Cellular Component [GO:0043209]    QuickGO    AmiGO