Which pericardium protects and anchors the heart?

The fibrous pericardium is the structure that provides protection and anchoring for the heart. This tough, dense connective tissue layer surrounds the heart and is attached to the diaphragm and the great vessels, helping to stabilize the position of the heart within the thoracic cavity. Its rigidity prevents overdistension of the heart and protects it from infections and trauma.

In contrast, the serous pericardium, which includes the visceral and parietal components, provides a lubricated sliding surface that reduces friction during heartbeats but does not provide the same level of anchoring as the fibrous pericardium. The visceral pericardium is a layer that directly covers the heart muscle, while the parietal pericardium is the outer layer of the serous pericardium that lines the fibrous pericardium. Neither of these layers has the structural properties necessary for anchoring.