Its a nice kids movie with a cool mix of animation and real life scenes (with Bill Murray! always fun). But don't expect an anatomically correct movie that will teach your kids (or yourself) in a fun way about the human body, most of the stuff in this movie is completely made up and scientifically not even remotely possible.
If you want your kids (or yourself) educated about the human body than there is a tv show that is way more suitable and actually has a lot of facts and real and correct information about the human body. You have to see: Once Upon a Time... Life