•The Heart (continued)

–The pericardium is a two-layered membrane that forms the U-shaped pericardial sac

▪Outer layer is the parietal pericardium

▪Inner layer is the epicardium

▪Pericardial fluid fills the space between the layers

•Heart Muscle

–The muscular myocardium lies beneath the epicardium

–The endocardium is the innermost layer that lines the heart’s chambers and valves