ANS vs neural structure

ANS and neural structure both are nouns.

Word	Noun	Adjective	Verb	Adverb
ANS	Yes	No	No	No
neural structure	Yes	No	No	No

As nouns, neural structure is a hypernym of ANS; that is, neural structure is a word with a broader meaning than ANS:

ANS: the part of the nervous system of vertebrates that controls involuntary actions of the smooth muscles and heart and glands
neural structure: a structure that is part of the nervous system

ANS (noun)	neural structure (noun)
the part of the nervous system of vertebrates that controls involuntary actions of the smooth muscles and heart and glands	a structure that is part of the nervous system