The Pericardium

The pericardium is a conical membranous sac in which the heart and the commencement of the great vessels are contained. It is placed behind the sternum and the cartilages of the third, fourth, fifth, sixth, and seventh ribs of the left side, in the interval between the pleurae.

It apex is directed upward and surrounds the great vessels about two inches above their origin from the base of the heart. Its base is attached to the central tendon and to the left part of the adjoining muscular structure of the Diaphragm.

In front it is separated from the sternum by the remains of the thymus gland above and a little loose areola tissue below, and is covered by the margins of the lungs, especially the left. Behind it rests upon the bronchi; the esophagus and the descending aorta. Laterally, it is covered by the pleura and is in relation to the inner surface of the lungs; the phrenic nerve with its accompanying vessel descend between the pericardium and pleura on either side.