What is the name of the muscular middle layer of the heart?

The muscular middle layer of the heart is called the myocardium. This layer is primarily responsible for the heart's ability to contract and pump blood throughout the circulatory system. The myocardium is composed of specialized cardiac muscle tissue that can contract in a coordinated manner, allowing for effective heartbeats.

The endocardium, which is one of the other layers of the heart, lines the interior of the heart chambers and helps to minimize friction as blood flows through the heart. The pericardium is a protective sac that surrounds the heart, providing lubrication and support. Finally, the epicardium is the outer layer of the heart wall and also serves as a protective layer. Understanding these distinct layers is crucial in cardiology, as each plays a vital role in heart function and health.