What does mesothelium mean?
Mesothelium is the thin layer of epithelium that lines the body's closed serous cavities and covers the organs within them. It forms, for example, the pleural layers around the lungs, the pericardial lining around the heart, and the peritoneal lining within the abdomen. The tissue consists chiefly of flattened mesothelial cells, whose smooth surfaces reduce friction as organs move. In medical and anatomical contexts, mesothelium can refer either to the tissue as a type or to a particular layer of it. Mesothelial cells can become inflamed in conditions such as pleuritis or peritonitis, while abnormalities in these cells are associated with mesothelioma, a cancer of the mesothelial lining. The term is technical rather than general, but it usefully identifies a specific anatomical structure: the delicate epithelial covering of serous membranes. It should not be confused with endothelium, which lines blood and lymphatic vessels, or with epithelium more generally, which is the broader category of tissue covering surfaces and lining cavities.
nounThe mesothelium is the thin layer of epithelium that lines the closed body cavities called serous cavities and covers the organs within them.
- The thin epithelial layer lining serous cavities and covering the organs within them.
"The mesothelium covering the lungs allows them to move smoothly against the chest wall."
"The mesothelium forms the smooth lining around the heart and lungs."
"Researchers examined the mesothelial cells for signs of inflammation."
The plural is used when referring to the mesothelial layers of different organs or anatomical cavities.
"Inflammation affected the mesothelia surrounding the lungs and heart."
The mesothelium is the body's friction-reducing lining, a delicate sheet that lets organs move smoothly within the chest and abdomen.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does mesothelium come from?
The word combines the combining form meso-, derived from Greek mesos meaning middle, with epithelium, from Greek epi, meaning upon, and thele, meaning nipple or skin. In anatomical terminology, mesothelium denotes the epithelium occupying an intermediate position between the body's outer surface and its internal tissues. The related terms mesoderm, mesenteron, and mesosphere also use the Greek root meaning middle, although in different anatomical or scientific contexts.
Related word forms
How mesothelium is actually used
This is a specialized medical and anatomical term, usually encountered in histology, surgery, and clinical discussion. It is most often used in the singular to refer to the tissue type, with the plural mesothelia used for layers in different anatomical locations.
Easily confused with mesothelium
Mesothelium lines closed serous cavities and covers their organs, whereas endothelium lines the interior of blood and lymphatic vessels.
Epithelium is the general term for tissue covering a surface or lining a cavity, while mesothelium specifically refers to the epithelial layer of serous membranes.