the fibrous sac covering of the heart which is in contact with the pleura is the
Pericardium The pericardium is a double-walled sac containing the heart and the roots of the great vessels. The pericardial sac has two layers, a serous layer and a fibrous layer. It encloses the pericardial cavity which contains pericardial fluid.
Pericardium The pericardium fixes the heart to the mediastinum, gives protection against infection, and provides the lubrication for the heart. It receives its name from Ancient Greek peri (περί; "around") and cardion (κάρδιον; "heart").