At the start of the ventricular systole, the mitral valve closes, to prevent the flow of blood hack into the atrium. As systole continues, blood from the right ventricle enters the pulmonary artery and blood from the left ventricle enters the aorta.
At the start of the ventricular systole, the mitral valve closes, to prevent the flow of blood hack into the atrium. As systole continues, blood from the right ventricle enters the pulmonary artery and blood from the left ventricle enters the aorta.