pericardium

The pericardium is a protective, double-layered sac that surrounds the heart. It contains a small amount of lubricating fluid, allowing the heart to move smoothly as it beats. The pericardium helps hold the heart in place within the chest, prevents it from over-expanding when blood volume increases, and provides a barrier against infections or complications from nearby organs. This structure is essential for maintaining the heart’s position and functioning properly, ensuring it operates efficiently within the chest cavity.