heart wall consists of how many layers
The wall of the heart is composed of three distinct layers. 2. The outermost layer, the epicardium, is made up of connective tissue and epithelium, and houses blood and lymph capillaries along with coronary arteries. 3. The middle myocardium consists of cardiac muscle and is the thickest layer of the heart wall. 4. The inner endocardium is smooth and is made up of connective tissue and epithelium, and is continuous with the endothelium of major vessels joining the heart. a. The endocardium houses Purkinje fibers.