What does the term 'endocardium' refer to?

The term 'endocardium' specifically refers to the inner layer of the heart. This layer is crucial in providing a smooth lining for the heart chambers and is composed of a thin layer of endothelial cells. These cells minimize friction as blood flows through the heart, thus playing an essential role in maintaining efficient circulation. The endocardium also helps to regulate the contraction of the heart by facilitating the conduction of electrical impulses. Understanding this terminology is vital for comprehending heart anatomy and physiology, particularly how each layer contributes to the overall function of the heart.