The basic function of the heart is to pump blood. Impure blood from the whole body returns to the right heart (right atrium) through veins. From there, with each heartbeat right ventricle will push the blood to the lungs through the pulmonary artery. Exchange of gases-removal of carbon dioxide from the blood and addition of oxygen obtained through breathing happens in the lungs. Thus, pure blood enters the left atrium and subsequently left ventricle pushes the blood to the main artery aorta. The aorta carries and supplies blood to various organs through canal coming out of the dam supplying water to different villages.Every organ and tissue like brain, intestine, muscle, lungs, bones, skin,eyes, nose, ears and heart itself also, need oxygen and nutrients. Similarly removal of metabolic wastes and carbon dioxide is also very much needed. Body accomplishes this through circulating blood.
The human Heart beats more than 1,00,000 times in 24 hours. It starts functioning when the child is in the womb of the mother and it continues pushing blood for 1,00,000 kilometres distance with each heartbeat till one lives. we all know the result if the heart gets tired and stops working !