Explain the function of the heart

The heart functions as a pump, circulating blood around the body to the cells. This is the medium for oxygen being delivered to the cells. The heart has two sides, left and right. Each one contains a ventricle and an atrium. The right side of the heart is responsible for pumping deoxygenated blood to the lungs, where waste products (CO2) are removed and it is oxygenated. Oxygenated blood is returned to the left atrium and flows through a valve to the left ventricle. The thick muscular wall of the left ventricle then contracts, forcing the blood out into the aorta and around the body. Deoxygenated blood returns to the right atrium.