Colorful animations and crisp video footage illustrate the vital process of circulation. The major characteristics and features of the circulatory systems are explored, with special emphasis placed on circulatory problems and caring for the circulatory system. Concepts and terminology include: pulmonary circulation, systemic circulation, blood, components of blood, blood vessels, arteries, veins, capillaries, heart, atria, ventricles, septum, valves, coronary arteries, pulse, heartbeat cycle, SA node, AV node, blood pressure, hypertension, and atherosclerosis.