sphincter muscle vs anatomical sphincter

sphincter muscle and anatomical sphincter both are nouns.

Word	Noun	Adjective	Verb	Adverb
sphincter muscle	Yes	No	No	No
anatomical sphincter	Yes	No	No	No

As nouns, sphincter muscle and anatomical sphincter are synonyms defined as:

sphincter muscle and anatomical sphincter: a ring of muscle that contracts to close an opening

Other synonyms of sphincter muscle include sphincter.

sphincter muscle (noun)	anatomical sphincter (noun)
a ring of muscle that contracts to close an opening	a ring of muscle that contracts to close an opening