What is The Cardiovascular System? The heart and circulatory system also called the cardiovascular system make up the network that delivers blood to the body‘s tissues. With each heartbeat, blood is sent throughout our bodies, carrying oxygen and nutrients to all of our cells. The circulatory system is composed of the heart and blood vessels, including arteries, veins, and capillaries. Our bodies actually have two circulatory systems: The  pulmonary circulation Is a short loop from the heart to the…