The Cardiovasular System is the human body system where the heart pumps blood through the blood vessels all throughout the body. In the heart,there are 4 chambers: Left Ventricle, Right Ventricle, Left Atrium, and the Right Atrium. The two atriums get the blood first then, it's sent down to the two ventricles to be pumped out. The heart also has 4 valves: Pulmonary Valve, Tricuspid Valve, Aortic Valve, and the Mitral Valve.