Pericardium Layers: Understanding Heart Protection

The pericardial layers that protect the heart consist of:

1. Epicardium: The epicardium is the outer layer of the pericardium. It is a thin, smooth, and transparent serous membrane that covers the surface of the heart. It is made of mesothelial cells, which are continuous with the mesothelial cells of the pleura. The epicardium also contains a network of blood vessels and nerves.

2. Myocardium: The myocardium is the middle layer of the pericardium. It is made of cardiac muscle fibers, which are responsible for the pumping action of the heart. The myocardium is also supplied by a network of blood vessels and nerves.

3. Endocardium: The endocardium is the inner layer of the pericardium. It is a thin, smooth, and glistening serous membrane that lines the inside of the heart, including the chambers, valves, and papillary muscles. It is made of mesothelial cells, which are continuous with the mesothelial cells of the endothelium. The endocardium also contains a network of blood vessels and nerves.