Mesothelium


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mesothelium

[‚me·zō′thē·lē·əm]
(anatomy)
The simple squamous-cell epithelium lining the pleural, pericardial, peritoneal, and scrotal cavities.
(embryology)
The lining of the wall of the primitive body cavity situated between the somatopleure and splanchnopleure.

Mesothelium

 

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 ?
Histological analysis of the MCs-seeded compound graft showed a single layer of mesothelium formed on the outer surface of the tissue tube after incubation for 7 days (Figure 2(e)).
To evaluate healing of the peritoneal mesothelium, which plays an important role in abdominal adhesion formation, we used immunohistochemistry to determine the expression of cytokeratin in the peritoneal mesothelial cells of the different groups.
Several barrier materials have been used clinically, including hyaluronic acid, carboxymethyl chitin, and oxidized regenerated cellulose, to prevent adhesion by separating the wounded tissues and promoting the repair of mesothelium cells [17-19].
Although many theories have been proposed to describe how the ovarian mesothelium could undergo metaplasia and dysplasia, perhaps the greatest gap in understanding the process of ovarian carcinogenesis from ovarian surface epithelium (OSE) is the recognition of a true precursor lesion of high-grade carcinoma in the ovary.
Although the pathogenesis is poorly understood, it is postulated that these tumours develop through serous or mucinous metaplasia of preexisting coelomic mesothelium. Surgical excision remains the mainstay of successful management.
It has been shown that under normal circumstances, mesothelin is present in several human tissues, including the mesothelium and is aberrantly expressed mainly by MM but also by pancreatic cancer, ovarian cancer or some breast and lung cancers [7,12,19].
It is a proliferation of mesothelium cells of the peritoneum, with a predilection for the pelvic viscera [2].
Most tumors are benign and, contrary to previous beliefs, they do not derive from the mesothelium but rather from dendritic interstitial cells, which express CD34 and have generalized distribution in tissues, a feature that helps to recognize them in other organs [2, 3].
It is significantly expressed by most ovarian epithelial tumors but also by the normal epithelium of the female reproductive system, gastrointestinal mucosal cells, and the luminal surface of mesothelium lining the peritoneum, pleura, and pericardium.
Mesothelioma is a cancerous tumour of the mesothelium, the lining of some of the major organs.
The surface mesothelium of normal serosa is derived from multipotent subserosal cells in the underlying layer of connective tissue.
Mesothelioma is an aggressive form of cancer that occurs in the mesothelium, the thin layer of tissue that covers the lungs and other organs.