What is Epithelium?
[[File:Illu epithelium.jpg|250px|right|Types of epithelium]] '''Epithelium''' (plural: epithelia) is one of the four main types of [[Tissue (biological)|tissue]] in the body of [[animals]]. It is made up of one or more layers of [[cell]]s. The outermost layer of the [[skin]] is a special type of epithelium. It has an important [[Function (biology)|function]]: it forms a mechanical [[wikt:defence|defence]] against [[infection]]: see [[innate immunity]]. Epithelia are found on the surface of [[organ (anatomy)|organs]] and many other parts of the body. One main function of epithelia is moving [[liquid|fluids]] into or out of an organ or body part. It also protects organs and carries [[sense organ]]s. There are many different types of epithelium that do different things in the body, including the [[excretory]] system. The epithelium covers blood vessels and hollow organs such as the [[stomach]] and kidneys. All glands are made from epithelial cells. In some areas, the epithelium secretes sweat, oil, or [[mucus]]. The functions of epithelial cells include secretion, selective absorption, protection, transcellular transport, and sensing. Epithelial layers have no blood vessels: they get oxygen and nourishment from the underlying [[connective tissue]], through their basement membrane.<ref>Ross M.H. & Pawlina W. 2015. ''Histology: a text and atlas: with correlated cell and molecular biology''. 7th ed, Lippincott Williams & Wilkins. pp. 528, 604. ISBN 978-1451187427</ref> ==Bibliography== {{reflist}} ==Other websites== *[https://www.britannica.com/science/epithelium Article from Encyclopedia Britannica regarding Epithelium] [[Category:Animal tissues]]