afferent vs centripetal

afferent is a noun but centripetal is not a noun.

Word	Noun	Adjective	Verb	Adverb
afferent	Yes	Yes	No	No
centripetal	No	Yes	No	No

afferent (noun)	centripetal (noun)
a nerve that passes impulses from receptors toward or to the central nervous system

afferent (adjective)	centripetal (adjective)
of nerves and nerve impulses; conveying sensory information from the sense organs to the CNS	tending to move toward a center
	of a nerve fiber or impulse originating outside and passing toward the central nervous system
	tending to unify