Heart its structure and function

Hearty is a pumping organ . it pump blood to all prats of the body. human heart is lie on the left side of the chest cavity . the heart is covered by tough double membrane called pericardium. this membrane protect the heart from mechanical injury . heart is composed of four chambers , auricles and ventricles. the auricle is smaller than the ventricle  . the anterior portion of the heart is made by auricle. the oxygenated and deoxygenated blood is separated from each other , like other mammals. the human herat beat is normally 72 beats per minutes . but these beaten of heart is increase to 120 during running or some other hard exercise .every time heart pour 85 millilitres of blood to aorta with high pressure.If the hearts beats are stop than death may occur.