The heart is one of the vital organs in the human body. Every minute, it pumps 4 to 5 liters of blood through the body’s circulatory system. This blood distributes oxygen and nutrients to all the muscles and organs in the body. The heart consists of four chambers:
- Left atrium: collects oxygenated blood that comes from the pulmonary artery after being oxygenated in the lungs.
- Left ventricle: pumps the oxygenated blood through the aorta to the rest of the body.
- Right atrium: collects deoxygenated blood from the tissues through the superior and inferior vena cava.
- Right ventricle: pumps the deoxygenated blood to the lungs so it becomes oxygenated.
Four heart valves control the opening and closing of each heart chamber, so that blood only flows one way through the heart. These valves are:
- Two atrioventricular valves which are located between the atria and ventricles. On the left side of the heart is the mitral valve, and on the right side of the heart is the tricuspid valve.
- Two semilunar valves which are located at the opening of the arteries that leave the heart. On the left side this is the aortic valve, and on the right side is the pulmonary valve.