Cardiovascular System: Main Components
The cardiovascular system transports hormones, gases (carbon dioxide and oxygen), food and metabolic wastes to and from cells. It consists of the following components: blood vessels (a vascular system: arteries, veins, and capillaries); blood (cells and liquid plasma); heart (a muscular pump unit that supplies blood and oxygen to all parts of the human body). The system consists of two types of circulations: pulmonary circulation; systemic circulation. An average adult contains from 4.7 to 5.7 liters of blood that generally consists of white blood cells, red blood cells, plasma, and platelets.