THORAX ABDOMEN AND PELVIS

Detailed explanation-1: -Between the layers is the pericardial cavity, a potential space filled with 15-50 milliliters of serous pericardial fluid. Pericardial fluid is secreted by pericardial cells, and it is this fluid that reduces friction between the parietal and visceral layer during heart contractions.

Detailed explanation-2: -A pericardial effusion refers to the accumulation of excess fluid in the pericardial sac surrounding the heart. In a healthy individual, the pericardial sac contains between 15 and 50 milliliters (mL) of serous fluid.

Detailed explanation-3: -Pericardial fluid is the serous fluid secreted by the serous layer of the pericardium into the pericardial cavity. The pericardium consists of two layers, an outer fibrous layer and the inner serous layer.