National Institutes of Health
Nih Curriculum Supplement for Middle School: Looking Good, Feeling Good
A great resource from the Office of Science Education which provides a curriculum for teaching about the musculoskeletal system, the skin system and how they interact. This curriculum emphasizes choices teens can make to ensure good...
abcteach
Abcteach: Science: Health and Nutrition
[Free Registration/Login Required] Elementary to middle school students can learn from the resources here about food and nutrition. In particular is a lesson plan and worksheet on the food pyramid guidelines issued by the USDA in 2005.
CK-12 Foundation
Ck 12: Life Science: 11.58 Autoimmune Disease
Learn about some autoimmune disorders that affect human health.