ANS vs autonomic nervous system

ANS and autonomic nervous system both are nouns.

Word	Noun	Adjective	Verb	Adverb
ANS	Yes	No	No	No
autonomic nervous system	Yes	No	No	No

As nouns, ANS and autonomic nervous system are synonyms defined as:

ANS and autonomic nervous system: the part of the nervous system of vertebrates that controls involuntary actions of the smooth muscles and heart and glands

ANS (noun)	autonomic nervous system (noun)
the part of the nervous system of vertebrates that controls involuntary actions of the smooth muscles and heart and glands	the part of the nervous system of vertebrates that controls involuntary actions of the smooth muscles and heart and glands