During a heart attack, some of the cells on the thick layer of muscle in the heart walls die. this layer of muscle is called the
a) epithelial tissue layer
b) pericardium
c) connective tissue layer
d) myocardium

Myocardium

The heart has four chambers, four valves. It is composed of cardiac muscles which all in all pumps blood throughout the human body through the blood vessels. When something gets injured around the heart, well it will automatically, in high possibility stop functioning. Take not of the valves and the most important is the sinoatrial node which is the pace maker of the heart. It is what triggers the heart to pump itself and the valves then function and the blood travels and then gets cleansed out of carbon dioxide in the alveoli.