The wall of the heart is made up of three layers: An outer layer called the pericardium It is a tough membrane like covering to protect the heart from expanding Unfortunately it may interfere with the flow of blood in the coronary arteries The middle layer is the thick heart muscle that is uniquely designed to contract in a circular fashion in order to squeeze blood into the circulation approximately once a second It is this layer that is called the myocardium The myocardium is lined with a smooth layer of tissue known as the endocardium It is in direct contact with the blood within the heart's chambers and prevents the blood from clotting inside of the heart
The myocardium is the the muscular wall of the heart; specifically the middle of the three layers forming the wall of the heart It is composed of cardiac muscle and forms the greater part of the heart wall The thickness reflects the magnitude of the pressure generated in the heart during contraction; the myocardium is thickest around the left ventricle which does most of the work in the heart
The muscles that surround and power the heart; blood is supplied by the coronary arteries
the muscular wall of the heart located between the inner endocardial layer and the outer epicardial layer