I was excited to find a site out of Japan that has shared anatomical obj models of bones, organs, muscles, and more. While not perfect, you can go browse their models here: http://lifesciencedb.jp/bp3d/ But, I have not been able to download from their browser directly. You can download all the files from a different part of their site: http://dbarchive.biosciencedbc.jp/en/bodyparts3d/download.html. So I first look up a model in their browser, find the model component and look if up in the folder. I will try some first prints this week!