Semilunar valves are O between ventricles and arteries O active are found veins O between arteries and atria Which cardiac cycle phase are semilunar valves open? ventricular ejection atrial contraction isovolumetric contraction O isovolumetric relaxation Blood leaving the pulmonary trunk enters the O pulmonary arteries O pulmonary veins right atrium O left atrium The heart as a metabolically active organ gets its blood supply from coronary arteries pulmonary circulation the lumen (hollow space) of the chambers O carotid artery