Warning: If you start teaching human anatomy to a four-year-old and five-year-old be prepared to hear things like: "I have to go empty my bladder now!" or "Evangeline emptied her intestines!" Or they may just start punching themselves in the head to show you how hard their skull or "bone helmet" is.
But on the plus side you'll discover how useful some parts of our body really are. For example, my kids love the fact that we wouldn't be able to stand right if we didn't have phalanges on our feet. It's a toss up whether pretending to not have toes and falling down is more fun than just saying "phalanges." Oh, and I never knew that such an uncute word such as "vertebrae" can suddenly become adorable when a four-year-old says it.
And while Lily is much more accurate than her brother when locating her femur bones, Malachi's impression of blood grabbing and soaking up oxygen from the lungs is quite a sight to be seen. At this point, I don't know if our decision to homeschool our kids is for their benefit or simply for the entertainment value. Either way, you can't get this kind of schooling anywhere other than the Gardner School of Life.