The cardiovascular system is also known as the circulatory system.
It is made up of the heart, the blood vessels namely arteries, veins and capillaries, and approximately five liters of blood.
The circulatory system's major functions are to transport oxygen, hormones, and nutrients to every cell in the body, and to tale away cellular waste products from the cells such as carbon dioxide and bring them to excretory organs where they are expelled out of the body.
The circulatory system is kept running by the heart, which is a muscular organ the size of the closed fist of an adult. It pumps about 5 liters of blood every minute throughout the body.
