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The simple squamous-cell epithelium lining the pleural, pericardial, peritoneal, and scrotal cavities.
The lining of the wall of the primitive body cavity situated between the somatopleure and splanchnopleure.



in vertebrates and man, the epithelial tissue that lines the serous membranes of the body cavity (peritoneum, pleura, pericardium).

Mesothelium is formed from mesoderm. It consists of a single layer of densely arranged flat polygonal cells. In lower vertebrates (cyclostomes, fish, amphibians), mesothelial cells are wholly or partly furnished with cilia. In mammals and man, the surfaces of the cells are covered with microvilli, which assist in the absorption and excretion of cavitary fluid. Mesothelium is highly sensitive to external influences. When the serous membranes are irritated and an inflammatory reaction results, the continuity of the mesothelial layer is interrupted, the cells are destroyed, and the underlying connective tissue is exposed. The connective tissue cells then penetrate the irritated area and phagocytize the dying tissue areas and, in septic inflammation, the bacteria. The connective tissue then proliferates, demarcating the focus of irritation and forming adhesions. Mesothelium grows over the adhesions, preventing them from further development and preventing visceral concrescence.

References in periodicals archive ?
The use of immunohistochemistry in distinguishing reactive from neoplastic mesothelium.
Mesothelioma is a form of cancer affecting the mesothelium, the thin lining of the inner surface of the chest wall.
My father-in-law, a robust man in his early 60's was recently diagnosed with Mesothelioma Mesothelioma is a cancer that orginates in the mesothelium tissues, the part of the body that holds different organs in place.
The mesothelium lining protects the lungs, heart and stomach by making a special fluid that allows the organs to move freely in the body.
Histologically, the mesothelium is a hydrophobic cell layer separating the peritoneum from systemic circulation (5, 6).
Mesothelioma is a rare form of cancer in which malignant cells are found in the mesothelium, a protective sac that covers most of the body's internal organs.
Wu et al (12) observed staining for X-linked inhibitor of apoptosis in 0 of 9 normal samples of normal mesothelium, 1 of 13 hyperplasia cases (8%), and 25 of 31 mesotheliomas (81%).
It is not clear whether mechanical stress related to ascites can stimulate mesothelium to produce CA 125 (4,6) or whether clearance of CA 125 by the diseased liver is impaired (4,5).
Posttraumatic cysts are formed either as a result of encapsulation of a hematoma or invagination of splenic surface mesothelium into splenic parenchyma following trauma.
The inner layer is made up of mesothelium with micropinocytotic vesicles.
Mesothelioma is a rare form of cancer affecting the mesothelium, or the protective lining around our internal organs.
The disease originates in the mesothelium, or the protective lining that covers many internal organs.