We found 4 Reddit comments about I Am Joe's Body (A Berkley/Reader's Digest Book). Here are the top ones, ranked by their Reddit score.
Just to be a pain in the ass, the "I am..." was not taken from a high school series on anatomy, but from a series of articles titled "I am Joe's/Jane's <insert body part here>" published in Readers Digest, later put into book form and titled I Am Joe's Body
Yes, seriously. "I am Joe's _____" (fill in the blank with a body part) articles were very popular in Reader's Digest.
He is referencing a series of Reader's Digest articles written from the perspective of a man's organs. In the book he uses Joe like the articles were written, the movie changes it to Jack for some reason or another. But it isn't the character's name it's just him playing with the theme of the article titles.
There was a whole series of them; I remember reading them in my grandpa's Readers' Digest as a kid. I found an anthology of them for sale on Amazon if you want to read them. They were all 'Joe,' except the body parts men don't have, which were 'Jane,' if I'm remembering correctly. So, 'I am Joe's lungs,' but 'I am Jane's uterus.'