Pericardial sac

Definition

The pericardial sac, also known as the pericardium, is a double-walled membrane that encloses the heart and the roots of the great vessels. It provides protection and lubrication to the heart, allowing it to beat in a relatively frictionless environment.

Related terms

Epicardium: The innermost layer of the pericardium that lies directly on the heart's surface, acting as a protective outer layer.

Myocardium:

The thick middle layer of the heart wall composed of cardiac muscle tissue that contracts to pump blood out of the heart.

Endocardium:

The innermost layer lining the interior of the heart chambers and valves, providing a smooth surface for blood flow