auricula vs auricular appendix

auricula and auricular appendix both are nouns.

Word	Noun	Adjective	Verb	Adverb
auricula	Yes	No	No	No
auricular appendix	Yes	No	No	No

As nouns, auricula and auricular appendix are synonyms defined as:

auricula and auricular appendix: a pouch projecting from the top front of each atrium of the heart

Other synonyms of auricula include auricular appendage.

auricula (noun)	auricular appendix (noun)
a pouch projecting from the top front of each atrium of the heart	a pouch projecting from the top front of each atrium of the heart
yellow-flowered primrose native to Alps; commonly cultivated