BioEd Online
Bio Ed Online: Microgravity
In this lesson middle schoolers will use water balloons to simulate the effects of gravity and microgravity on fluid distribution in the body.
American Heart Association
American Heart Association: Low Blood Pressure
Presents low blood pressure as a common side effect of pregnancy, some medications, and other circumstances, but as an indication of a potential problem if associated with a provided list of warning signs and symptoms.
WebMD
Web Md: Blood Pressure
This site from WebMD Health provides great information on blood pressure. The basic overview discusses what blood pressure is, shows a picture of it, gives a chart to mark it, and includes several links for additional information.