Today people strive to great lengths to keep their body in a good, healthy condition. Every system in the body, let it be digestion, circulatory (of blood), immune, respiratory, cellular respiratory or kidneys and excretion are all vital. Each have their separate roles, but not one works separately....

The Heart and the Circulatory System Introduction Imagine that you are living in the year 1535, and that you don't feel well. You have had some problems with fatigue, feeling a little more tired than usual when you walked to the market and back. You tell this to your physician, and he sends y...