Form a fist. That’s the size of your heart. Your heart is not very big, but it does an important job. You body can’t work or live without it. How does your heart work? What are the different parts of the heart? In this paper we will try to answer these questions. Hearty Words to know…. CHowirculatory System: this is the part of your body that includes your heart and blood vessels Ventricles: the two lower parts of the heart. One is called the right ventricle and one is called the left ventricle. Valves: there are four in the heart. They are like doors that open and close to let the blood in and out. Atria: The two upper parts of the heart. One is the right atrium and one is the left atrium. Aorta: the largest artery in our body. It carries blood away from the heart. What are the main parts of the heart? The five main parts of the heart are the right and left ventricles, aorta, and right and left atria. They are all a part of the Circulatory System. The aorta is the largest artery in our body. It goes from the left ventricle and circulates blood through the body. When you look at a picture of the heart it seems confusing because the right ventricle and atrium are on the left side of the picture and the left ventricle and atrium are on the right side of the picture. The ventricles are at the bottom of each side of the heart and the atria are at the top. How does your heart work? Oxygen poor blood from the body enters and fills the right atrium. At the same time oxygen rich blood from the lungs enters and fills the left atrium. When the valves open, blood in the artia is pumped into the right and left ventricles. When the right ventricle pumps blood to the lungs the left ventricle pumps blood out to the rest of the body. Oxygen rich blood: blood that has a high amount of oxygen What is the main job of the heart? The main job of the heart is to pump blood all over your body so that all of our organs can get the oxygen they need to keep working. Oxygen poor blood: blood that has a low amount of oxygen Did you know? Your heart weighs about one pound. Your heart pumps about one million barrels of blood in your lifetime. The blood vessels fed by your heart are 60,000 miles long. Sources: www.2030site.org/fun/facts.html The Heart by Seymour Simon.