what are the two chambers
Full Answer. In addition to two upper chambers, the heart also has two lower chambers. The lower chambers are known as the left and right ventricles, which have a primary responsibility of pumping blood out of the heart. Separating the upper and lower chambers are different valves, which control the direction and rate of blood flow. A complete circulating cycle is defined as each instance the two atria bring in blood and the ventricles pump out blood.