The human heart is a pump made of muscle that pushes blood through the human body. The heart contains the aorta, anterior vena cava, semilunar valve, right atrium, right ventride, posterior vena cava, pulmonary artery, pulmonary vein, septum and left ventricle.
The process of the heart pumping blood through the body is known as the cardiac cycle, and this cycle occurs roughly 72 times every minute. The blood that is pumped through the body nourishes the cells throughout. Once the blood has given nourishment to the cells, it is drawn into the right half of the heart, sent to the lungs to be re-oxygenated, drawn into the left half of the heart, and then pumped back into the body to nourish the cells again.