The mesothelium is a membrane that forms the lining of several body cavities: the pleura (thoracal cavity), peritoneum (abdominal cavity) and pericardium (heart sac). Mesothelial tissue also surrounds the male internal reproductive organs (the tunica vaginalis testis) and covers the internal reproductive organs of women (the tunica serosa uteri). In anatomy, the pleural cavity is the potential space between the lungs and the chest wall. ... In higher vertebrates, the peritoneum is the serous membrane that forms the lining of the abdominal cavity - it covers most of the intra-abdominal organs. ... The pericardium is a double-walled sac that contains the heart and the roots of the great vessels. ... The Tunica Vaginalis is the serous covering of the testis. ...

Origin

Mesothelium derives from the embryonic mesoderm cell layer, that lines the coelom (body cavity) in the embryo. It develops into the layer of cells that covers and protects most of the internal organs of the body. It is composed of two layers of cells: It has been suggested that embryology be merged into this article or section. ... Organs derived from each germ layer. ... By the broadest definition, a body cavity is any fluid filled space in a multicellular organism. ...

• One layer that immediately surrounds the organ (visceral);
• A sac around the cavity (parietal).

A layer of mesothelial cells grown in cell culture, featuring the typical "cobblestone" appearance

Image File history File linksMetadata Size of this preview: 800 × 600 pixelsFull resolution (1280 × 960 pixel, file size: 300 KB, MIME type: image/jpeg) Confluent human peritoneal mesothelial cells, third passage. ... Image File history File linksMetadata Size of this preview: 800 × 600 pixelsFull resolution (1280 × 960 pixel, file size: 300 KB, MIME type: image/jpeg) Confluent human peritoneal mesothelial cells, third passage. ... Epithelial cells in culture, stained for keratin (red) and DNA (green) Cell culture is the term applied when cells are grown in a synthetic environment. ... A cobblestone-covered street Cobblestones are stones used in the pavement of early streets. ...

Function

The mesothelium is composed of an extensive monolayer of specialized cells (mesothelial cells) that line the body's serous cavities and internal organs. The main purpose of these cells is to produce a lubricating fluid that is released between layers, providing a slippery, non-adhesive and protective surface to facilitate intracoelomic movement.

The mesothelium is also implicated in the transport and movement of fluid and particulate matter across the serosal cavities, leucocyte migration in response to inflammatory mediators, synthesis of pro-inflammatory cytokines, growth factors and extracellular matrix proteins to aid in serosal repair, and the release of factors to promote the disposition and clearance of fibrin (such as plasminogen). It is an antigen presenting cell. Furthermore, the secretion of glycosaminoglycans and lubricants may protect the body against infection and tumor dissemination. White Blood Cells is also the name of a White Stripes album. ... Cytokines are small protein molecules that are the core of communication between immune system cells, and even between immune system cells and cells belonging to other tissue types. ... Growth factor is any of about twenty small proteins that attach to specific receptors on the surface of stem cells in bone marrow and promote differentiation and maturation of these cells into morphotic constituents of blood. ... In biology, extracellular matrix (ECM) is any material part of a tissue that is not part of any cell. ... Fibrin is a protein involved in the clotting of blood. ... Plasmin is an important degrading enzyme (EC 3. ... An antigen presenting cell (APC) is a cell that displays foreign antigen complexed with MHC on its surface. ... Wikipedia does not yet have an article with this exact name. ...

Role in disease

• Mesothelioma: (cancer of the mesothelium) is a disease in which cells of the mesothelium become abnormal and divide without control or order. They can invade and damage nearby tissues and organs. Cancer cells can also metastasize (spread) from their original site to other parts of the body. Most cases of mesothelioma begin in the pleura or peritoneum. More than 90% of mesothelioma cases are linked to asbestos exposure.

• Intra-abdominal adhesions: Normally, the mesothelium secrets plasminogen, which inhibits the formation of fibrin. As mesothelium lacks tight junctions, an ultrastructure that closely links cells together (as seen in epithelia), it is prone to shedding during surgery. The reduced plasminogen activity of exposed surfaces can cause fibrin adhesions to form with other surfaces, leading to intra-abdominal (or rarely intra-thoracal) adhesions.

• Ultrafiltration failure: The peritoneal mesothelium is implicated in in the long-term development of ultrafiltration failure in peritoneal dialysis patients. The presence of supra-physiological glucose concentrations, acidity, and glucose degradation products contribute to the fibrosis of the peritoneal mesothelium, either by epithelial-mesenchymal transition or increased proliferation of existing fibroblasts. A fibrosed peritoneum is not a very good exchanger of fluids and solutes, resulting in ultrafiltration failure.

Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these to spread, either by direct growth into adjacent tissue through invasion, or by implantation into distant sites by metastasis (where cancer cells are transported through the bloodstream or lymphatic system). ... Fibrous asbestos on muscovite Asbestos Asbestos Asbestos (a misapplication of Latin: asbestos quicklime from Greek : a, not and sbestos, extinguishable) describes any of a group of minerals that can be fibrous, many of which are metamorphic and are hydrous magnesium silicates. ... Plasmin is an important degrading enzyme (EC 3. ... Fibrin is a protein involved in the clotting of blood. ... Diagram of Tight junction. ... Types of epithelium This article discusses the epithelium as it relates to animal anatomy. ... A cardiothoracic surgeon performs a mitral valve replacement at the Fitzsimons Army Medical Center. ... Peritoneal dialysis In medicine, peritoneal dialysis is a method for removing waste such as urea and potassium from the blood, as well as excess fluid, when the kidneys are incapable of this (i. ... Fibrosis is the formation or development of excess fibrous connective tissue in an organ or tissue as a reparative or reactive process, as opposed to formation of fibrous tissue as a normal constituent of an organ or tissue. ... Epithelial-mesenchymal transition (EMT) is a program of development of biological cells characterized by loss of cell adhesion, repression of E-cadherin expression, and increased cell mobility. ... A fibroblast is a cell that makes the structural fibers and ground substance of connective tissue. ...

Sources

• Mesothelioma: Questions and Answers (National Cancer Institute).
• Histology at KUMC epithel-epith01 "Mesothelium"
• Histology at BU 00102loa - "Tissues, Layers, and Organs: transverse section of rat gut"
• Mutsaers SE. Mesothelial cells: Their structure, function, and role in serosal repair. Respirology 2002; 7:171-191