The<unk>  is deeper than the fibrous pericardium.  It contains two layers, both of which function in lubricating the heart to prevent friction from occurring during heart activity:
The layer next to the fibrous pericardium is the parietal layer.
The layer deep to the fibrous pericardium is the visceral layer. When this layer comes into contact with the heart (not the great vessels), it is known as the epicardium.
Together these two layers form a continuous uninterrupted membrane. Between these two layers exists a small cavity called the pericardial cavity, which contains a supply of<unk>  fluid. The<unk>  fluid that is found in this space is known as the pericardial fluid.
Serous pericardium
Fibrous pericardium
Epicardial fat pad
Epicardium
Apex of the heart
Base of the heart
Sternum
Interventricular septum