EVERYDAY SCIENCE

Detailed explanation-1: -The pericardium is a fibrous sac that encloses the heart and great vessels. It keeps the heart in a stable location in the mediastinum, facilitates its movements, and separates it from the lungs and other mediastinal structures. It also supports physiological cardiac function.[1][2][3]

Detailed explanation-2: -The pericardium is a tough fibroelastic sac which covers the heart from all sides except at the cardiac root (where the great vessels join the heart) and the bottom (where only the serous pericardium exists to cover the upper surface of the central tendon of diaphragm).

Detailed explanation-3: -The epicardium refers to the outermost protective layer of the heart. The epicardium is composed of mesothelium, a cell type that covers and protects most of the internal organs of the body as well as fat and connective tissue.

Detailed explanation-4: -The pericardium acts as mechanical protection for the heart and big vessels, and a lubrication to reduce friction between the heart and the surrounding structures. A very important role in all aspects of pericardial functions is played by mesothelial cells.