Anatomy and Physiology of the Pericardium.

The pericardium consists of a visceral mesothelial monolayer (epicardium) that reflects over the great vessels and joins an outer, relatively inelastic fibrous parietal layer of organized collagen and elastin fibers, between which is a potential space that normally contains up to 50 mL of plasma filtrate. Although not essential for life, the pericardium serves important albeit subtle functions in the euvolemic healthy individual that become increasingly important in hypervolemic states and conditions in which the heart enlarges acutely. The pericardial functions can be divided into the mechanical, reflex, membranous, metabolic, ligamentous.