Question

Write the two functions of pericardial fluid.

Answer 1

Hint:The word pericardial is made by - peri (Around/surrounding) + Cardial (relating to cardiovascular/ heart).Pericardial fluid is the serous fluid secreted by the serous layer of the pericardium into the pericardial cavity.

Complete answer:
1)The pericardium is a fibrous sac that encloses the heart and great vessels. It keeps the heart in a stable location in the mediastinum, facilitates its movements, and separates it from the lungs and other mediastinal structures. It also supports physiological cardiac function. It has two layers. The outer layer is fibrous and is called parietal pericardium. The inner layer is known as visceral pericardium. The visceral pericardium also secretes a fluid called pericardial fluid.
2) The pericardial sac positions the heart in the mediastinum and limits its motion while providing a lubricated slippery surface for the heart to beat inside and the lungs to move outside. The pericardium prevents the excessive dilatation of the heart, and in pathological states, it can limit the overfilling of the heart, which would result in low cardiac output. It also influences the pressure-volume relationships of cardiac chambers by providing limited space for the heart as a whole., and acts as a mechanical barrier to infection.
There are following functions of pericardial fluid-
The pericardial fluid equalizes hydrostatic, inertial, and gravitational forces, maintains the geometry of the left ventricle.The fluid minimizes the friction generated between the membrane during the process of contraction and relaxation of the heart.
It works as a shock absorber as it absorbs outside shock and prevents the heart from suffering mechanical injury.

Note:Normally there is no space between parietal and visceral pleura and between pericardium and heart therefore, the spaces lack the pericardial fluid.A pericardial effusion is a condition where there is the presence of excessive pericardial fluid.