spinal nerve root vs posterior horn

spinal nerve root and posterior horn both are nouns.

Word	Noun	Adjective	Verb	Adverb
spinal nerve root	Yes	No	No	No
posterior horn	Yes	No	No	No

spinal nerve root (noun)	posterior horn (noun)
one of two roots of the spinal nerves	one of two roots of a spinal nerve that passes dorsally from the spinal cord and that consists of sensory fibers