The main function of the circulatory system is to transport blood throughout the body, delivering essential nutrients and oxygen to cells while removing waste products like carbon dioxide. Composed of the heart, blood vessels, and blood, this system plays a crucial role in maintaining homeostasis. It also helps regulate body temperature and pH levels. Additionally, the circulatory system is responsible for transporting hormones and immune cells, playing a key role in overall health and functioning. Proper circulation is vital for sustaining life and ensuring that organs and tissues receive the resources they need.