The three functions of the circulatory system include maintaining normal body temperature, helping the body fight disease and providing the ideal chemical balance for homeostasis. The circulatory system consists of the heart, arteries, veins and blood.
The organs and vessels in the circulatory system regulate the flow of blood, oxygen and other gases, hormones and nutrients to and from cells. Three types of circulation occur in the body. In pulmonary circulation, oxygen-depleted blood moves from the heart to the lungs, while oxygenated blood moves from the lungs to the heart.
Systemic circulation moves oxygenated blood from the heart to the rest of the body, and coronary circulation ensures that the heart has adequate blood to work properly. This ensures that waste is carried away and that the body maintains a stable internal environment.