The heart wall consists of three layers: epicardium, myocardium and endocardium. The epicardium, the outer membrane of the heart is the same as the visceral layer of the serous pericardium. The myocardium, which is beneath the epicardium, is the actual heart muscle. The endocardium is the membrane that lines the inside of the heart. This layer also lines the inner layer of the blood vessels (endothelium), thus the blood is transported in a continuous channel through the cardiovascular system.