The Left Ventricle
Blood arrives in the left ventricle as it comes through the mitral valve. Bllod collects in the left ventricle and stretches the muscle, when the muscle is stretched enough it contracts or squeezes the blood forward through the aortic valve out to the body. Notice the left ventricle muscle is bigger then the right ventricle muscle because the left has to push blood all through the body, the right ventricle only has to push blood to the lungs.