ventral root vs motor nerve

ventral root and motor nerve both are nouns.

Word	Noun	Adjective	Verb	Adverb
ventral root	Yes	No	No	No
motor nerve	Yes	No	No	No

As nouns, motor nerve is a hypernym of ventral root; that is, motor nerve is a word with a broader meaning than ventral root:

ventral root: one of the two roots of a spinal nerve that passes ventrally from the spinal cord and that consists of motor fibers
motor nerve: a nerve that conveys impulses toward or to muscles or glands

Other hypernyms of ventral root include efferent, efferent nerve.

ventral root (noun)	motor nerve (noun)
one of the two roots of a spinal nerve that passes ventrally from the spinal cord and that consists of motor fibers	a nerve that conveys impulses toward or to muscles or glands