The Fibrous Pericardium is the outer layer of the pericardial sac. Fibrous connective tissue bands connect the fibrous pericardium to the sternum and the diaphragm.
The Serous Pericardium
is composed of an outer parietal layer fused to the fibrous pericardium and
an inner visceral layer (epicardium) adhered to the myocardium. The pericardial
space between these two serous layers contains a thin film of fluid.