The circulatory system acts as a transport service for cells in the human body, that are not in direct contact with the external environment.The two fluids, blood and lymph, flow through the circulatory system. The blood, the heart and the blood vessels move from the cardiovascular system. The lymph, lymph nodes, and lymph vessels move from the lymohatic system. These systems make up the circulatory system. Really the circulatory system is divided into three parts: the pulmonary circulation (the lungs), coronary circulation (the heart) and systemic circulation (the rest of the system). The circulatory system's job is to transport materials throughout the entire body. It transports nutrients, water, and oxygen to billions of body cells and carries away wastes such as carbon dioxide.