ABSTRACT
The cardiovascular system includes the heart and all the blood vessels that ramify throughout the body; it is traditionally divided into two sides. The left side of the cardiovascular system refers to the arterial side, containing oxygenated blood; the right is the venous side, containing deoxygenated blood. The left side of the heart pumps oxygenated blood round the body. The right side of the heart collects the venous, or deoxygenated, blood from the body and pumps it through the lungs. These two systems, therefore, work in series, with each red blood cell starting from the left side of the heart, traversing the blood vessels of the body, back to the right side of the heart, through the lungs and then back again to the left side of the heart.
