A cardiovascular system (often called circulatory system) is an organ system that moves substances to and from cells; it can also help stabilize body temperature and pH (part of homeostasis). The main role of the cardiovascular system in the body is to transport oxygen to all tissues in the body and for removing, from these same tissues, metabolic waste products. 

Components

The main components of the circulatory system are the heart, the blood, and the blood vessels. The system of blood vessels consists of  arteries, capillaries and veins.

Arteries bring oxygenated blood to the tissues, and veins bring deoxygenated blood back to the heart. Blood passes from arteries to veins through capillaries, which are the thinnest and most numerous of the blood vessels.

Deoxygenated blood (containing little or no oxygen) collects in two major veins: the superior vena cava and the inferior vena cava. The superior and inferior vena cava empty into the right atrium. The right atrium is the larger of the two atriums because it needs to be able to hold the larger amount of blood coming from the body (as opposed to the amount coming from the lungs). The blood is then pumped through the tricuspid atrioventicular valve into the right ventricle. From the right ventricle, blood is pumped through the pulmonary semi-lunar valve into the pulmonary trunk. The deoxygenated blood leaves the heart by the pulmonary arteries and travels through the lungs (where it is oxygenated) and into the pulmonary vein. The oxygenated blood then enters the left atrium. The blood then travels through the bicuspid valve, or mitral valve, into the left ventricle. The left ventricle is thicker and more muscular than the right ventricle because it pumps blood throughout the body, systemic circulation. From the left ventricle, blood is pumped through the semi-lunar valve into the aorta. Once the blood goes through systemic circulation, deoxygenated blood will again collect inside the vena cava and the process will continue.

Measurement techniques

• Electrocardiogram
• Sphygmomanometer
• Pulse meter

See also

• Cardiology
• Lymphatic system
• Noise health effects

External links

• Cardiovascular Topics
• Studies on Hemodynamics and Coronary Circulation
• The Circulatory System, a comprehensive overview
• The InVision Guide to a Healthy Heart An interactive website