Final answer:
The fibrous pericardium is a tough, fibrous, double-walled sac that surrounds the heart. The pericardium consists of two sublayers: the sturdy outer fibrous pericardium and the inner serous pericardium. The pericardial cavity is filled with lubricating serous fluid and lies between the epicardium and the pericardium.
Step-by-step explanation:
The fibrous pericardium is a tough, fibrous, double-walled sac that surrounds the heart. It is made of dense connective tissue and protects the heart while maintaining its position in the thorax.
The fibrous pericardium is part of the pericardium, which is the membrane that directly surrounds the heart. The pericardium consists of two sublayers: the sturdy outer fibrous pericardium and the inner serous pericardium.
The pericardium also includes the more delicate serous pericardium, which consists of the parietal pericardium fused to the fibrous pericardium, and the inner visceral pericardium, or epicardium, fused to the heart. The pericardial cavity, filled with lubricating serous fluid, lies between the epicardium and the pericardium.