epithelium

American  

[ep-uh-thee-lee-uhm] / ˌɛp əˈθi li əm /

noun

Biology.

plural

epitheliums, epithelia

1. 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.

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epithelium British  

/ ˌɛpɪˈθiːlɪəm /

noun

1. 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

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epithelium Scientific  

/ ĕp′ə-thē′lē-əm /

plural

epithelia

1. 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.

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Other Word Forms

• epithelial
  adjective

Etymology

Origin of epithelium

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

Compare meaning

How does epithelium compare to similar and commonly confused words? Explore the most common comparisons:

• endothelium vs. epithelium

Example Sentences

"Barrett's esophagus is characterized by the replacement of the resident squamous epithelium of the esophagus by other cell types that are not normally found in this tissue," says the scientist.

From Science Daily • Apr. 11, 2024

The inhaled air is trapped on the olfactory epithelium and/or the Jacobson’s organ, giving kitties an extra chance to detect scent molecules.

From National Geographic • Jan. 2, 2024

"Repair-specific proliferative cells mainly contribute to the epithelium -- the thin outer layer -- of the newly formed tentacle."

From Science Daily • Dec. 22, 2023

Some of these cells extend to the surface of the epithelium, but they are very thin at the top.

From Textbooks • Jan. 1, 2015

Clearly I did, because here I am at his kitchen table with the fragrance of an omelet smothered in some kind of tomatoey-oniony-garlicky sauce tickling my olfactory epithelium.

From "Odd One Out" by Nic Stone