Parietal pericardium:This is the outer layer of a cone-shaped fibrous sac that encases the heart and the origins of the major blood vessels. The pericardium consists of two layers: an outer and an inner layer. The outer layer is sturdy and thick, providing a loose covering for the heart and connecting to the central area of the diaphragm and the rear of the sternum (breastbone). The inner layer is double-layered, with one layer tightly attached to the heart and the other lining the inner surface of the outer layer. The space between these layers contains a small amount of fluid that serves as a lubricant, enabling smooth heart movement within the chest. The term "pericardium" translates to "around the heart." The inner layer that closely wraps the heart is known as the visceral pericardium or epicardium.
