transitional 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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transitional epithelium

n.

Stratified epithelium in which the individual layers are formed by a transformation of the cells from the layer below.

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transitional epithelium,

a form of stratified epithelium found characteristically in the mucous membrane of ureter and bladder; in the contracted condition it consists of many cell layers, whereas in the stretched condition fewer layers can be distinguished.