The space that separates the parietal and visceral pericardium is known as the pericardial cavity. This cavity contains a small amount of pericardial fluid, which acts as a lubricant, allowing the heart to move smoothly within the thoracic cavity as it beats.
The parietal pericardium is the outer layer of the pericardium, a fibrous sac that provides protection and anchors the heart within the chest. In contrast, the visceral pericardium, also called the epicardium, is the inner layer that is directly attached to the surface of the heart.
Thus, the pericardial cavity plays an essential role in facilitating the heart’s function while providing necessary cushioning and support at the same time. Without this separation and the fluid it contains, the friction between the heart and surrounding structures could lead to discomfort and complications.