A smooth tissue membrane comprising of two mesothelium layers that discharge serous fluid is known as a serous membrane. The inner layer that envelopes the viscera (organs) in the body cavities is known as the visceral membrane. A second layer of the serous membrane's epithelial cells known as the parietal layer envelopes the body wall.
In order to do surgery of a heart, the surgeon first has to go through the serous membrane, which surrounds the lungs in the pleural cavity known as the pleura. After that, the surgeon has to go through the parietal pericardium and the visceral pericardium also known as epicardium.
