Perikardiaõõn

Perikardiaõõn, also known as the pericardial cavity, is the potential space between the two layers of the serous pericardium, the visceral pericardium and the parietal pericardium. The visceral pericardium is the layer that adheres directly to the surface of the heart, while the parietal pericardium forms the outer wall of the sac surrounding the heart. This space is not an anatomical cavity in the true sense, as it normally contains only a very small amount of serous fluid, typically 15-50 mL.

The pericardial fluid is crucial for the normal functioning of the heart. It acts as a lubricant, allowing the heart to beat smoothly within the pericardial sac with minimal friction. The fluid reduces the mechanical stress on the heart during its constant contractions and relaxations. The pressure within the pericardial cavity is normally subatmospheric, meaning it is lower than the atmospheric pressure.

Under certain pathological conditions, the amount of fluid within the pericardial cavity can increase significantly. This accumulation of excess fluid is known as pericardial effusion. When the effusion becomes large enough to compress the heart and impede its ability to fill and pump blood effectively, it is termed cardiac tamponade. This is a medical emergency that requires prompt intervention to remove the excess fluid. Conditions that can lead to pericardial effusion include inflammation of the pericardium (pericarditis) due to infections, autoimmune diseases, or post-heart attack complications, as well as certain cancers and kidney failure.