The University of Pennsylvania Health System has a great web site with medical animations. The animations show and explain many different medical problems, anatomy and physiology and the human body.
As I viewed different animations I quickly realized how useful this can be in a classroom. Health, Biology, Anatomy and Physiology, Emergency Medical Technician, Paramedic, Pre-med and Nursing students will all find this site useful as they learn about the human body and it's systems.
The site is easy to navigate, with a listing of all of the animations on one page. They are sorted by topic/body system. There are animations about each body system, diseases, pregnancy, surgeries, and medical problems.
You will need to make sure you have Adobe Flash, Adobe Shockwave, and Quicktime installed on your computer to view the animations.