In the heart, a ventricle's a heart chamber which collects blood from an atrium (another heart chamber that's smaller than a ventricle) and pumps it out of the heart. In a four-chambered heart, such as that in humans, there're two ventricles: the right ventricle pumps blood into the pulmonary circulation for the lungs, and the left ventricle pumps blood into the systemic circulation through the aorta for the rest of the body. (See Double circulatory system for details.) Ventricles have thicker w… (More on Ventricular)