myelinated nerve fiber vs medullated nerve fiber

myelinated nerve fiber and medullated nerve fiber both are nouns.

Word	Noun	Adjective	Verb	Adverb
myelinated nerve fiber	Yes	No	No	No
medullated nerve fiber	Yes	No	No	No

As nouns, myelinated nerve fiber and medullated nerve fiber are synonyms defined as:

myelinated nerve fiber and medullated nerve fiber: a nerve fiber encased in a sheath of myelin

myelinated nerve fiber (noun)	medullated nerve fiber (noun)
a nerve fiber encased in a sheath of myelin	a nerve fiber encased in a sheath of myelin