The cardiovascular (circulatory) system is our body's transportation system. It consists of a pump, the heart, and an enormous network of pathways, the blood vessels. But what is blood and how does it circulate through our bodies? What other parts of the body work with the cardiovascular system? Your heart beats more than one hundred thousand times a day. In this film we explore the cardiovascular system: hemoglobin transports oxygen in the red blood cells, how blood delivers nutrients and disposes of waste; the role of white blood cells in fighting disease and infections; the components of blood, the role of platelets and the function and structure of the heart; pulmonary and systemic circulation; blood vessels - arteries, capillaries and veins; blood pressure and pulse; and how to keep your heart healthy.