Pericardial cavity

The pericardial cavity is defined as the potential space located between the visceral layer (epicardium) and the parietal layer of the serous pericardium. This cavity normally contains a small amount (0.3 to 1 mL in dogs) of a clear, light yellow serous fluid, which serves to lubricate the heart and facilitate its movement within the pericardial sac during the cardiac cycle.

The pericardial cavity is bounded externally by the parietal pericardium, which lines the inner surface of the fibrous pericardium, and internally by the visceral pericardium, which is adherent to the heart surface.