The pericardial cavity is formed by which structures?

• A. Visceral and parietal serous layers
• B. Myocardium and epicardium
• C. Visceral and fibrous layers
• D. Parietal and endocardial layers

Answer: (A)

The pericardial cavity is the potential space between the two layers of serous pericardium—the visceral layer that covers the heart (epicardium) and the parietal layer that lines the fibrous pericardium. This space contains a small amount of lubricating fluid to reduce friction as the heart beats. The fibrous pericardium is a tough outer layer that anchors the sac, but it does not form the cavity itself. The other options mix structures that aren’t what forms this space: the myocardium is heart muscle, the endocardium lines the heart chambers, and the fibrous layer is not the serous boundary separating the cavity.