ANATOMY

Detailed explanation-1: -Myocardium-the middle, muscular layer. Endocardium-the inner layer.

Detailed explanation-2: -The outer layer of the heart wall is the epicardium, the middle layer is the myocardium, and the inner layer is the endocardium.

Detailed explanation-3: -Myocardium. The middle layer of the heart wall is the myocardium-the muscle tissue of the heart and the thickest layer of the heart wall. It is composed of cardiac muscle cells, or cardiomyocytes.

Detailed explanation-4: -The wall of the heart separates into the following layers: epicardium, myocardium, and endocardium. These three layers of the heart are embryologically equivalent to the three layers of blood vessels: tunica adventitia, tunica media, and tunica intima, respectively.