medullated nerve fiber vs myelinated nerve fiber

medullated nerve fiber and myelinated nerve fiber both are nouns.

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

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

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

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