As an introduction to the skeletal and muscular systems, we read and discussed two great library books by Seymour Simon this week: Bones and Muscles. After reading these, I surprised Gerrick with our own new copy of DK The Complete Human Body. It has fantastic illustrations and I'm sure we will refer to it often.
He also enjoyed building a skeleton in Build a Body on Spongelab. This is a free site; however, it does require registration with an email address. He liked that it was realistic/non-cartoonish, so for us it was definitely worth the extra effort to register. (Build a Body is also available as a free iPad app. We don't have an iPad yet, but for those of you who do, check it out!)
You can find more of our BFSU-inspired science activities here.