Definition for Epicardium
From Biology Forums Dictionary
Epicardium describes the outer layer of Heart tissue. When considered as a part of the Pericardium, it is the inner layer, or visceral pericardium, continuous with the serous layer.
Its largest constituent is Connective tissue and functions as a protective layer. The visceral pericardium apparently produces the Pericardial fluid, which lubricates motion between the inner and outer layers of the Pericardium.