Crossword clues for epithelium
The Collaborative International Dictionary
Epithelium \Ep`i*the"li*um\, n.; pl. E. Epitheliums, L. Epithelia. [NL., fr. Gr. 'epi` upon + ? nipple.] (Anat.) The superficial layer of cells lining the alimentary canal and all its appendages, all glands and their ducts, blood vessels and lymphatics, serous cavities, etc. It often includes the epidermis (i. e., keratin-producing epithelial cells), and it is sometimes restricted to the alimentary canal, the glands and their appendages, -- the term endothelium being applied to the lining membrane of the blood vessels, lymphatics, and serous cavities.
Douglas Harper's Etymology Dictionary
n. (context anatomy English) A membranous tissue composed of one or more layers of cells which forms the covering of most internal and external surfaces of the body and its organs: internally including the lining of vessels and other small cavities, and externally being the skin.
Epithelium (epi- + thele + -ium) is one of the four basic types of animal tissue. The other three types are connective tissue, muscle tissue and nervous tissue. Epithelial tissues line the cavities and surfaces of blood vessels and organs throughout the body.
There are three principal shapes of epithelial cells: squamous, columnar, and cuboidal. These can be arranged in a single layer of cells as simple epithelium, either squamous, columnar or cuboidal, or in layers of two or more cells deep as stratified (layered), either squamous, columnar or cuboidal. All glands are made up of epithelial cells. Functions of epithelial cells include secretion, selective absorption, protection, transcellular transport, and sensing.
Epithelial layers contain no blood vessels, so they must receive nourishment via diffusion of substances from the underlying connective tissue, through the basement membrane.
Usage examples of "epithelium".
In a case of Sangster, reported by Politzer, although most of the dermoids, as usual, were like fibroma-nodules and therefore the color of normal skin, those over the mastoid processes and clavicle were lemon-yellow, and were generally thought to be xanthoma until they were excised, and Politzer found they were typical dermoid cysts with the usual contents of degenerated epithelium and hair.
Its two epithelia, the outer and the inner, the ectoderm and the entoderm, proved to be primitive organs out of whose foldings-in and -out, were developed the glands, the tissues, the sensory organs, the body processes.
There should be edema fluid in the alveolar spaces with disproportionate autolytic change of the respiratory epithelium.