When was your last anatomy lesson? Click here. Here is a terrific video animation of the cardiac cycle (which I came across this week at Meddy Bear's Facebook page). Simple and easy to understand, it shows the sequence of events in a single heart beat: The Cardiac Cycle The video very clearly shows the major blood vessels (both arteries and veins) that shunt blood into or out of the heart chambers (i.e., the two atria and two ventricles). Notice how important the heart valves ar...