What is the epicardium?

What is the epicardium?

• A. The outermost layer of the heart wall, also known as the visceral serous pericardium.
• B. The middle, muscular layer of the heart wall.
• C. The inner lining of the heart chambers.
• D. The fibrous outer protective layer of the heart.

Answer: (A)

The epicardium is the outermost layer of the heart wall, and it is the visceral layer of the serous pericardium that covers the heart’s surface. This layer directly coats the heart and is continuous with the parietal layer of the serous pericardium at the roots of the great vessels. Between the visceral (epicardial) layer and the parietal layer lies the pericardial cavity, which contains fluid to reduce friction as the heart beats. The epicardium also houses the coronary vessels that nourish the heart muscle. The middle muscular layer is the myocardium, the inner lining of the chambers is the endocardium, and the fibrous outer protective layer is the fibrous pericardium.

The epicardium is the outermost layer of the heart wall, and it is the visceral layer of the serous pericardium that covers the heart’s surface. This layer directly coats the heart and is continuous with the parietal layer of the serous pericardium at the roots of the great vessels. Between the visceral (epicardial) layer and the parietal layer lies the pericardial cavity, which contains fluid to reduce friction as the heart beats. The epicardium also houses the coronary vessels that nourish the heart muscle. The middle muscular layer is the myocardium, the inner lining of the chambers is the endocardium, and the fibrous outer protective layer is the fibrous pericardium.