Where is the myocardium located?
The myocardium is located between the endocardium and the visceral layer of the serous membrane (epicardium) of the heart.
The myocardium is the muscle of the heart. This muscle is supplied by arteries that branch off the aorta. So everytime the heart beats it pushes blood into the aorta and thus into systemic circulation and thus into the heart wall, as well. These arteries that supply the myocardium are called coronary arteries.
The myocardium is part of the most superficial layer of the heart. It is the middle of these three. The myocardium forms the bulk of the heart, and it consists mainly of cardiac muscle. This is the layer that sactually contracts. The myocardium's elongated, circularly and spirally arranged networks of cardiac mucle cells squeeze blood through the heart in the proper directions.