pericardial fluid
Yes, it is.
The pericardium surrounds the heart like a protective sac. It contains fluid that decreases friction.
The pericardium. It is composed of two layers: the fibrous pericardium (the outer layer that is made of tough connective tissue) and the serous pericardium (the inner layer in which serous fluid provides lubrication for the heart to beat with almost no friction).
There are three layers to the pericardium. They go in alphabetical order. The first layer is the Fibrous Pericardium. The second layer is the parietal pericardium and the third and innermost layer is the visceral layer.
Fibrous pericardium and serous pericardium. The serous pericardium is made up of an outer parietal layer that is fused to the fibrous pericardium and an inner visceral layer (aka epicardium) that is a layer of the heart wall and adheres tightly to the heart.
The membrane surrounding the heart is called the pericardium. It is a fluid sac that serves several purposes. One of the purposes of the pericardium is it contains the heart in the chest cavity. The pericardium also prevents the heart from overexpanding when the blood volume in the heart increases.
Epicardium or inner layer of serous pericardium is the innermost layer of pericardium.
The serous pericardium is a thin, double-layered membrane that covers the heart and consists of the parietal pericardium (outer layer) and visceral pericardium or epicardium (inner layer). The fibrous pericardium is a tough, fibrous layer that surrounds the serous pericardium and helps protect the heart and anchor it within the chest cavity.
The heart is encased in two protective layers. The outer layer -- the pericardium -- covers the heart. It folds in on itself at the aorta forming the epicardium of the heart. Between these layers is a small amount of fluid (10-50 ml) that affords the layers a non-stick surface.
The pericardium is the layer of the heart formed by a single sheet of squamous epithelial cells covering connective tissue. It acts as a protective membrane around the heart and prevents friction as the heart beats.
Parietal Pericardium
Because every organ has 2 layers of tissue and fluid to prevent friction the inner layer I believe is visceral and the outside is parietal. such as the visceral pericardium and parietal pericardium protect the heart.