visceral serous pericardium (anatomy)
Last reviewed 01/2018
The visceral serous pericardium, or epicardium, is the deeper of the two layers of the serous pericardium. It is a mesothelial sheet that lies superficial and closely adherent to the surface of the heart.
Superficial to the serous pericardium is the pericardial cavity. This is defined by the layers of the visceral pericardium and the parietal pericardium that lies more superficially. Bridging the pericardial cavity, the visceral pericardium envelopes the great vessels of the heart and some of the areas between them. It is continuous with the parietal pericardium.
The mesothelium of the visceral pericardium secretes a serous fluid that lubricates the pericardial cavity.
During development, the regression of part of the dorsal mesocardium leads to the formation of the oblique and transverse sinuses separating the parietal and visceral layers.