What is "epicardium"?

The epicardium, also known as the visceral layer of the serous pericardium, is the outermost layer of the heart. It is composed of connective tissue and adipose (fat) tissue. The epicardium helps to protect and lubricate the heart, allowing it to contract and relax smoothly within the pericardial cavity. It also plays a role in the blood supply to the heart by housing small blood vessels that nourish the heart muscle.