What is another function of the pericardium in relation to blood volume?

The pericardium, which is the fibrous sac surrounding the heart, plays a crucial role in maintaining the heart's structure and function. One of its important functions is to prevent the heart from overfilling with blood. This is particularly significant because excessive blood volume can lead to distension of the heart, which could impair its ability to pump effectively. The pericardium maintains a certain amount of fluid between its layers, which acts as a cushion and allows for heart movement while also providing a barrier that limits the maximal stretch of the heart. By restricting overfilling, the pericardium helps to ensure that the heart maintains optimal function and efficiency in blood circulation.