Cardiovascular

This is an article about circulation in animals. For transport in plants, see Vascular tissue. For the band, see Circulatory System. Human circulatory system. arteries shown as red, veins blue. A circulatory system (cardiovascular system in biology classes) is an organ system that moves substances to and from cells; it can also help stabilize body temperature and pH (part of homeostasis). There are three types of circulatory systems (from simplest to most complex): no circulatory sys ...