complex body part vs anatomical structure

complex body part and anatomical structure both are nouns.

Word	Noun	Adjective	Verb	Adverb
complex body part	Yes	No	No	No
anatomical structure	Yes	No	No	No

As nouns, complex body part and anatomical structure are synonyms defined as:

complex body part and anatomical structure: a particular complex anatomical part of a living thing and its construction and arrangement

Other synonyms of complex body part include bodily structure, body structure, structure.

complex body part (noun)	anatomical structure (noun)
a particular complex anatomical part of a living thing and its construction and arrangement	a particular complex anatomical part of a living thing and its construction and arrangement