What are the two layers of the pericardium?

The two layers of the pericardium are the visceral layer and the parietal layer. The visceral layer is actually the inner layer that directly covers the heart, while the parietal layer forms the outer boundary of the pericardium. This arrangement allows the pericardial cavity to form between these two layers, filled with pericardial fluid which reduces friction as the heart beats.

The choice that states "serous and fibrous" combines terms that refer to specific properties of pericardial layers but does not accurately represent the conventional terminology used for the distinct layers of the pericardium. The serous component relates to the visceral and parietal layers collectively, while the fibrous layer refers to the tough outer fibrous pericardium, which is separate from the serous pericardium consisting of those two layers. The internal and external terminology is ambiguous and does not correspond with the established identity of the pericardial layers. The myocardial and endothelial choice incorrectly refers to heart tissue layers rather than pericardial structures. Understanding the anatomy of the pericardium is crucial for perfusionists since it accommodates the heart's movements and contributes to cardiac function.