squamous epithelium

epithelium /ep·i·the·li·um/ (-the´le-um) pl. epithe´lia   [Gr.] the cellular covering of internal and external body surfaces, including the lining of vessels and small cavities. It consists of cells joined by small amounts of cementing substances and is classified according to the number of layers and the shape of the cells.

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ciliated epithelium  that bearing vibratile cilia on the free surface.

columnar epithelium  that composed of columnar cells.

cuboidal epithelium  that composed of cuboidal cells.

glandular epithelium  that composed of secreting cells.

olfactory epithelium  pseudostratified epithelium lining the olfactory region of the nasal cavity and containing the receptors for the sense of smell.

Schematic diagram of the receptors in the olfactory epithelium.

pseudostratified epithelium  a type that looks stratified but is not, because its cells are arranged with their nuclei at different levels.

seminiferous epithelium  stratified epithelium lining the seminiferous tubules of the testis.

simple epithelium  that composed of a single layer of cells.

squamous epithelium  that composed of squamous cells.

stratified epithelium  that composed of cells arranged in layers.

transitional epithelium  that characteristically found lining hollow organs that are subject to great mechanical change due to contraction and distention; originally thought to represent a transition between stratified squamous and columnar epithelium.

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squamous epithelium

n.

Epithelium consisting of one or more cell layers, the most superficial of which is composed of flat, scalelike or platelike cells.

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squamous epithelium

Etymology: L, squama, scale; Gk, epi, above, thele, nipple

a sheet of flattened scalelike cells, attached together at the edges. Also called pavement epithelium.

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epithelium [ep″ĭ-the´le-um] (pl. epithe´lia) (Gr.)

the cellular covering of internal and external surfaces of the body, including the lining of vessels and other small cavities. It consists of cells joined by small amounts of cementing substances. Epithelium is classified into types on the basis of the number of layers deep and the shape of the superficial cells.

ciliated epithelium epithelium bearing vibratile, hairlike processes (cilia) on its free surface.

columnar epithelium epithelium whose cells are of much greater height than width.

cuboidal epithelium epithelium whose cells are of approximately the same height and width, and appear square in transverse section.

germinal epithelium thickened peritoneal epithelium covering the gonad from earliest development; formerly thought to give rise to germ cells.

glandular epithelium that composed of secreting cells.

pigmentary epithelium (pigmented epithelium) that made of cells containing granules of pigment.

sense epithelium (sensory epithelium) neuroepithelium (def. 1).

simple epithelium that composed of a single layer of cells.

squamous epithelium that composed of flattened platelike cells.

stratified epithelium epithelium made up of cells arranged in layers.

transitional epithelium a type characteristically found lining hollow organs, such as the urinary bladder, that are subject to great mechanical change due to contraction and distention; originally thought to represent a transition between stratified squamous and columnar epithelium.

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epithelium (ep´ithē´lēm),

n the layer of cells that lines a body cavity; cells may be ciliated or unciliated, and may be squamous (flat, scalelike), cuboidal (cube-shaped), or columnar (column-shaped).

epithelium, basement membrane of,

n See membrane, basement.

epithelium, desmosomes of

(dez´mosōmz´),
n an electronmicroscopic finding of intercellular bridges that serve to attach adjacent epithelial cells to each other.

epithelium, enamel, inner,

n the innermost layer of cells (ameloblasts) of the enamel organ that deposit the organic matrix of the enamel on the crown of the developing tooth. Also the innermost layer of Hertwig's epithelial root sheath.

epithelium, enamel, outer,

n the outermost layer of cells of the enamel organ. It is separated from the inner enamel epithelium in the area of the developing crown by the stratum intermedium and stellate reticulum and lies immediately adjacent to the inner enamel epithelium in the area of the developing root.

epithelium, enamel, reduced,

n combined enamel epithelium; the remains of the enamel organ after enamel formation is complete. After eruption of the tip of the crown, that part of the combined epithelium remaining on the enamel surface is called the
epithelial attachment.

epithelium, gingival,

n a stratified squamous epithelium consisting of a basal layer; it is keratinized or parakeratinized.

epithelium, hyperplastic,

n an increase in thickness, with alterations in structure, produced by proliferation of cellular elements of epithelium.

epithelium, oral,

n the epithelial covering of the oral mucosa. Composed of stratified squamous epithelium of varying thickness and varying degrees of keratinization.

epithelium, pocket,

n the epithelium that lines the periodontal pocket. Its most prominent characteristics are the presence of hyperplasia and ulceration.

epithelium, pseudostratified

(soo´dōstrat´ifīd),
n a type of epithelium in which there appears to be several layers (or strata) of cells, but all cells actually are resting on the base layer. Often ciliated and occurs only in mucosa.

epithelium, squamous

n a type of epithelium consisting of flat, scalelike cells.

epithelium, stratified squamous,

n the variety of epithelium covering the oral mucosa and dermal surfaces; composed of layers of cells oriented parallel to the surface. The various layers of cells in order from basement membrane to surface are stratum germinativum, stratum spinosum (prickle cell layer), and stratum lucidum (in dermal epithelium). The gingival epithelium generally exhibits some degree of keratinization, variable from parakeratinization to orthokeratinization within the layers of the stratum granulosum (granular layer) and stratum corneum (keratin layer).

epithelium, sulcal,

n the stratified squamous epithelium forming the covering of the soft tissue wall of the gingival sulcus, or crevice. Extends from the gingival margin to the line of attachment of the epithelium to the tooth surface.