What is one characteristic of the endocardium?

The endocardium is the innermost layer of the heart, and it serves an essential function by lining the heart chambers and heart valves. This characteristic is critical because it helps maintain a smooth surface for blood flow, reducing friction as blood moves through the heart. The endocardium is also composed of endothelial cells, which contribute to the formation of the heart's surface and ensure that the interior of the heart is protected and functions effectively.

While the endocardium does have some resilience, it is primarily its role in lining that distinguishes it from other layers of the heart. The elastic and flexible nature, as well as strength, are features attributed more to other structures in the heart, such as the myocardium, which is responsible for the contractile function of the heart. Thus, recognizing the specific role of the endocardium in lining the chambers and valves ensures a better understanding of cardiac anatomy and function.