The circulatory system contains of the heart, liver, lungs, kidneys, veins and arteries. The circulatory system is on of the most important system in you body because it is in charge of taking blood all over your body.

From the moment the human heart starts beating until the moment it stops, it pumps more then half a billion times. Your heat pumps about 72 times a minute, and pumps more or less five quarts of blood per minute. Your heart fills up with blood and then releases it to all the parts of your body including the lungs and the liver. Veins give your heart blood and your arteries take it away. The heart is located in the center of your chest slightly to the left. It is a muscle about the size of your fist.
Your heart has 2 chambers, they are call the left and right ventricle. The human heart is surrounded by veins and arteries such as Superior and Inferior vena cava. The Arteries are the Aorta. Its job is to pump your blood and keep the blood moving through your body. And your job is to keep it healty and pumping.