annexa vs body part

annexa and body part both are nouns.

Word	Noun	Adjective	Verb	Adverb
annexa	Yes	No	No	No
body part	Yes	No	No	No

As nouns, body part is a hypernym of annexa; that is, body part is a word with a broader meaning than annexa:

annexa: accessory or adjoining anatomical parts or appendages to an organ (especially of the embryo)
body part: any part of an organism such as an organ or extremity

annexa (noun)	body part (noun)
accessory or adjoining anatomical parts or appendages to an organ (especially of the embryo)	any part of an organism such as an organ or extremity