We also have the DK book and like it.

In addition to that, even more fun is a small plastic anatomy model with organs that come out and must be put back in, a bit like a puzzle. Ours came with a card discussing each organ. For example, http://www.lakeshorelearning.com/seo/ca%7CsearchResults~~p%7CZZ11~~.jsp This isn't the one we have, but similar.