The muscular middle layer of the heart wall is called the?

The muscular middle layer of the heart wall is called the?

• A. Myocardium
• B. Endocardium
• C. Epicardium
• D. Pericardium

Answer: (A)

The muscular middle layer is the myocardium. It’s made of cardiac muscle fibers arranged to produce the heart’s pumping action, with intercalated discs that allow tightly coordinated, rhythmic contractions. This layer sits between the inner lining, the endocardium, and the outer covering, the epicardium. The endocardium lines the heart chambers and valves, the epicardium is the outer layer that forms part of the visceral pericardium, and the pericardium is the fibrous sac surrounding the heart. The myocardium is thicker in the ventricles because they generate the higher pressures needed to propel blood through the body and lungs.

The muscular middle layer is the myocardium. It’s made of cardiac muscle fibers arranged to produce the heart’s pumping action, with intercalated discs that allow tightly coordinated, rhythmic contractions. This layer sits between the inner lining, the endocardium, and the outer covering, the epicardium. The endocardium lines the heart chambers and valves, the epicardium is the outer layer that forms part of the visceral pericardium, and the pericardium is the fibrous sac surrounding the heart. The myocardium is thicker in the ventricles because they generate the higher pressures needed to propel blood through the body and lungs.