The circulatory system is one of the most important systems in the body. It is made up of the heart, lungs, blood vessels and blood. Your heart plays and important part in being healthy. It keeps all the blood in your circulatory system flowing. Blood helps oxygen get around your body. When you exercise you can feel your pulse, it tells you how fast your heart is pumping.
The body's circulatory system is responsible for delivering food (nutrients), water and oxygen to the cells in your body. It also carries away waste such as carbon dioxide that body cells produce.