sphincter muscle vs sphincter

sphincter muscle and sphincter both are nouns.

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

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

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

Other synonyms of sphincter muscle include anatomical sphincter.

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