Describe and explain the structure of the human heart.

The human heart has four chambers, the right atrium, the right ventricle, the left atrium and the left ventricle. The right and left sides are completely seperated by the septum, this is so that the oxgenated blood and deoxygenated blood are kept seprate and are not able to mix, allowing for maximum oxygenation. The left side carries oxygenated blood and the right side carries deoxygenated blood. There are four sets of valves, two sets of semi-lunar valves, one set between the right ventricle and the pulmonary artery and the other set between the left ventricle and the aorta. There are also two sets of atrioventricular (AV) valves, one set between the right atrium and the right ventricle, which is called the tricuspid valve, the other set of AV valves are between the left atrium and the left ventricle, which is called the bicuspid valve. The valves in the heart are required to prevent backflow of the blood. The ventricle walls are thicker than those of the atria because the ventricles have to pump blood out of the heart to different parts of the body so require more strength to do this, where as the atria only have to pump blood into the ventricles. The left ventricle wall is thicker than the right ventricle wall because the left ventricle has to pump blood to the whole body, where as the right ventricle only pumps blood to the lungs, which is a shorter distance.