The circulatory system supplies nourishment and oxygen to all of our organs and tissues through an intricate network of arteries and veins. The heart is the key organ in that system. The heart is divided into four chambers - - the right atrium and right ventricle and the left atrium and left ventricle. Blood enters your heart through the right atrium, and is then pumped into the right ventricle. The right ventricle sends the blood to the lungs, where carbon dioxide is removed from the blood, and oxygen is added.

Once the blood is oxygenated, it moves to the left atrium. After collecting the blood, the left atrium sends it to the left ventricle, which is the main pumping chamber of the heart. The left ventricle is responsible for pumping the blood through the aorta and out to all of your organs and tissues.

The heart supplies its own needs through the coronary arteries on its surface. All our major arteries initially branch out from the aorta, to form the arterial portion of the circulatory system. Smaller vessels, called arterioles branch off from the arteries, and these branch off even further to become tiny vessels called capillaries. Capillaries play a huge role in the circulatory system, since they are directly responsible for providing oxygen and nutrients to the tissues and for “picking up” the carbon dioxide and waste products. Much of this waste is then filtered out of the blood through the liver and kidneys. The blood is then returned to the heart, where it begins the entire journey again.

Our hearts pump close to 2 thousand gallons of blood each day and, over our lifetime, beats more than 2 billion times without stopping.