cavity vs body structure

cavity and body structure both are nouns.

Word	Noun	Adjective	Verb	Adverb
cavity	Yes	No	No	No
body structure	Yes	No	No	No

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

cavity: (anatomy) a natural hollow or sinus within the body
body structure: a particular complex anatomical part of a living thing and its construction and arrangement

Other hypernyms of cavity include anatomical structure, bodily structure, complex body part, structure.

cavity (noun)	body structure (noun)
(anatomy) a natural hollow or sinus within the body	a particular complex anatomical part of a living thing and its construction and arrangement
a sizeable hole (usually in the ground)
soft decayed area in a tooth; progressive decay can lead to the death of a tooth
space that is surrounded by something