Part 1 of Essay
Introduction You need your heart for all your body needs. It pumps about 2000 gallons of blood a day. It takes about 20 seconds for blood to reach every cell in the body. An artery carries blood out from the heart. A vein carries blood back to the heart. An average adult heart weighs about 10-13 ounces (300 to 350 gra ....

Part 2 of Essay
.... vein takes the blood out of the heart and takes it to the lungs. Today we will talk about many different parts of the heart: The Three Layers of Muscle, Atriums, Ventricles, Systole and Diastole, Treatments for the Heart, Valves, and many Diseases. The Three Layers of Muscle The heart has three layers of a muscular wall. A thin layer of tissue, the pericardium covers the outside, and another layer, the endocardium, lines the inside. The myocardium is the middle layer and is the biggest of all ....