Myocardium:The myocardium is the thick middle layer of the heart wall composed of cardiac muscle tissue that contracts to pump blood out of the heart.
Pericardium:The pericardium is a double-walled sac containing the heart and the roots of its major vessels, serving to protect and lubricate the heart to reduce friction during its movements.
Valves: Heart valves are flap-like structures within the heart that open and close with each heartbeat to regulate one-way blood flow through the heart chambers