Assertion: gray matter's axon | /r/HasProperty | wrapped by insulating substance
Facets:
Source sentences:
text: Many axons are wrapped by an insulating substance called myelin, which is actually made from glial cells.
text: Many axons are wrapped by an insulating substance called myelin, which is actually made from glial cells.
text: Many axons are wrapped by an insulating substance called myelin, which is actually made from glial cells.