tissue vs body part

tissue and body part both are nouns.

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

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

tissue: part of an organism consisting of an aggregate of cells having a similar structure and function
body part: any part of an organism such as an organ or extremity

tissue (noun)	body part (noun)
part of an organism consisting of an aggregate of cells having a similar structure and function	any part of an organism such as an organ or extremity
a soft thin (usually translucent) paper

tissue (verb)	body part (verb)
create a piece of cloth by interlacing strands of fabric, such as wool or cotton