The circulatory system consists of three independent systems that work together: the heart (cardiovascular), lungs (pulmonary), and arteries, veins, coronary and portal vessels (systemic). The ...

How Does Blood Travel Through the Heart? As the heart beats, it pumps blood through a system of blood vessels, called the circulatory system. The vessels are elastic, muscular tubes that carry ...

How does your heart work? Find out how the heart keeps all the blood in your circulatory system flowing.