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Epithelium is an anatomical term for a basic type of bodily tissue. It comprises the external surface of the skin, the internal surfaces of the digestive, respiratory and urogenital systems, the closed serous cavities, the inner coats of the vessels, the acini and ducts of the secreting and excreting glands, the ventricles of the brain and the central canal of the spinal cord. The constituent cells of an epithelium are always closely packed together and the intercellular substance is reduced to a minimum. The cells comprising an epithelium are arranged in one (simple epithelium) or more (stratified epithelium and transitional epithelium) layers, usually supported on a basement membrane and united together by a cement-like substance which is chemically similar to the matrix or ground-substance of the connective tissues.
The epithelium serves various purposes. The epithelium of the skin (known as the epidermis) serves primarily to protect the underlying tissue (the true skin, nerves and vessels which it contains). Th epithelium of the salivary glands, the pancreas, the gastric glands and the glands of the small intestine are comprised of cells which prepare the digestive juices. The cells comprising the epithelium of the intestinal villi are concerned with the absorption of the products of digestion. The cells of the epitheliums of the serous cavities provide a smooth, moist surface. Rather unusually in the body, the epithelium is devoid of a blood supply
 Research Epithelium
A basement is the outer wall of the ground story of a building, or of a part of that story, when treated as a distinct substructure and also describes the rooms of a ground floor, collectively.
Research Basement
In architecture, a dado is that part of a pedestal included between the base and the cornice (or surbase), and in a wall, that part of the basement included between the base and the base course. In interior decoration, the dado is the lower part of the wall of an apartment when adorned with mouldings, or otherwise specially decorated.
Research Dado
In architecture a stereobate is the lower part or basement of a building or pedestal. The term is used loosely for several different forms of basement.
Research Stereobate
In architecture a substruction is the under building, foundation, or any preliminary structure intended to raise the lower floor or basement of a building above the natural level of the ground.
Research Substruction
In architecture the term superstructure refers to all that part of a building above the basement.
Research Superstructure
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The Probert Encyclopaedia was designed, edited and programed by
Matt and Leela Probert
©1993 - 2009 The Probert Encyclopaedia
Southampton, United Kingdom
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