epithelium

[ ep-uh-thee-lee-uhm ]

Phonetic (Standard)IPA

noun

, Biology.

, plural ep·i·the·li·ums, ep·i·the·li·a [ep-, uh, -, thee, -lee-, uh].

any plant or animal tissue that covers a surface or lines a cavity, and that also performs any of various secretory, transporting, or regulatory functions.

epithelium

/ ˌɛpɪˈθiːlɪəm /

an animal tissue consisting of one or more layers of closely packed cells covering the external and internal surfaces of the body. The cells vary in structure according to their function, which may be protective, secretory, or absorptive

epithelium

/ ĕp′ə-thē′lē-əm /

, Plural epithelia

The thin, membranous tissue that lines most of the internal and external surfaces of an animal's body. Epithelium is composed of one or more layers of densely packed cells. In vertebrates, it lines the outer layer of the skin (epidermis), the surface of most body cavities, and the lumen of fluid-filled organs, such as the gut or intestine.

First recorded in 1740–50; from New Latin, from Greek epi- epi- ( def ) + thēl(ḗ) “teat” + New Latin -ium -ium ( def )

C18: New Latin, from epi- + Greek thēlē nipple

They always imply desquamation of epithelium, which rarely occurs except in parenchymatous inflammations (Figs. 60 and 61).

The finely granular variety is the least significant, and is found when the epithelium is only moderately affected.

Granular and fatty casts, therefore, always indicate partial or complete disintegration of the renal epithelium.

The surface epithelial cells of a stratified epithelium are also of this type (fig. 4).

It occurs as the covering epithelium of the alveoli of the lung, of the kidney glomerules and capsule, &c.

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