Anatomy Arcade is a really neat site that has online games and interactive resources to help students learn about the anatomy of the human body. The games themselves are divided up by body systems. For example, you can click on games, then choose games about the skeletal system, articular system, muscle system, circulatory, respiratory, nervous, digestive, endocrine, and general.
Anatomy Arcade would be a great resource for Elementary Students just starting to learn about the Human Body Systems, or for students needing an extension to your current class curriculum.
You can check out Anatomy Arcade at: http://www.anatomyarcade.com