Pumps, Pipes and Flows

The heart was at one time thought to be the very seat of life and personality, and indeed we still speak of black hearted villains and soft hearted aunts. This was so presumably because the most obvious immediate sign of death was cessation of the heart beat. We now know that the heart is just a blood pump, or more correctly a pair of pumps, which are responsible for keeping the major transport system of the body in continuous motion. This knowledge has not decreased the importance of the heart because at normal body temperature we cannot survive a cardiac arrest of more than a few minutes.