The circulatory system is the body's blood transporting system. The cells of the body get their food from blood. The oxygen is important to blood and to cells because oxygen is necessary for cell growth and energy.
What the Heart & Circulatory System Do The circulatory system works closely with other systems in our bodies. It supplies oxygen and nutrients to our bodies by working with the respiratory system. At the same time, the circulatory system helps carry waste and carbon dioxide out of the body.
With each heartbeat, blood is sent throughout our bodies, carrying oxygen and nutrients to every cell. Every day, the approximately 10 pints (5 liters) of blood in your body travel many times through about 60,000 miles (96,560 kilometers) of blood vessels that branch and cross, linking the cells of our organs and body parts.
