What is the function of the pericadium?

The pericardium is a double-walled sac that surrounds the heart, serving several vital functions. It provides a protective barrier against infections and physical trauma, helps to anchor the heart in its position within the thoracic cavity, and reduces friction between the heart and surrounding structures during heartbeats. Additionally, the pericardial fluid within the sac facilitates smooth movement of the heart as it contracts and relaxes.