Ok, thank you!epicardium has dual role, functions as the outermost layer of heart wall as well as innermost layer of heart covering (Visceral layer of serous pericardium)oh, okay. But isn't the epicardium part of the pericardium?The pericardium is a sac enclosing the heart or surrounding the heart wall, rather than being an actual layer of the heart wall.
so heart wall - from innermost - endocardium (covers the valves also and is continuous with endothelium of blood vessels)
heart coverings (pericardium) from innermost - Visceral layer of serous pericardium (same as epicardium)
Parietal layer of serous pericardium (separated from visceral layer by pericardial space and fluid)