What is the mesothelium?

Question

What is the mesothelium?

Answer 1

epithelium derived from mesoderm that lines the body cavity of a vertebrate embryo and gives rise to epithelia (as of the peritoneum, pericardium, and pleurae), striated muscle, heart muscle, and several minor structures

Answer 2

The mesothelium is a membrane that covers and protects most of the internal organs of the body. It is composed of two layers of cells: One layer immediately surrounds the organ; the other forms a sac around it. The mesothelium produces a lubricating fluid that is released between these layers, allowing moving organs (such as the beating heart and the expanding and contracting lungs) to glide easily against adjacent structures.