Brush border

Brush border

A brush border (or striated border) is the name for the microvilli-covered surface of pseudostratified columnar epithelium and simple columnar epithelium found in multiple locations of the body. Microvilli are approximately 100 nanometers in diameter and their length varies from approximately 100 to 2,000 nanometers in length. Because individual microvilli are so small and are tightly packed in the brush border, individual microvilli can only be resolved using electron microscopes; [BUHistology|21901loa] with a light microscope they can usually only be seen collectively as a fuzzy fringe at the surface of the epithelium. This fuzzy appearance gave rise to the term brush border, as early anatomists noted that this structure appeared very much like the bristles of a paintbrush.

They are found in two main locations:

* The small intestine tract: This is where absorption takes place. [BUHistology|12202loa] [BUHistology|11703loa] [ [http://www.pathguy.com/histo/085.htm Basic Histology - Intestinal Columnar Epithelium ] ] The brush borders of the intestinal lining are the site of terminal carbohydrate digestions. The microvilli that constitute the brush border have enzymes for this final part of digestion anchored into their apical plasma membrane as integral membrane proteins. These enzymes are found near to the transporters that will then allow absorption of the digested nutrients.

* The kidney: Here the brush border is useful in distinguishing the proximal tubule (which possesses the brush border) from the distal tubule (which does not). [OklahomaHistology|35_19 - Kidney] [KansasHistology|urinary|renal13 "Tubules"]

ee also

*Brush border cell

References


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Look at other dictionaries:

  • brush border — brəsh n a stria of microvilli on the plasma membrane of an epithelial cell (as in a kidney tubule) that is specialized for absorption * * * see microvillus * * * a specialization of the free surface of certain cells, consisting of minute cylindri …   Medical dictionary

  • Brush border cell — A brush border cell is a type of cell functioning as an epithelium with a brush border as in the respiratory portion of the lungs.They are narrow columnar cells with short apical microvilli. They have afferent nerve endings and act as sensory… …   Wikipedia

  • brush border — noun Etymology: brush (III) : a striated border on the cells forming the membrane proper in certain epithelial membranes (as in that of the proximal convoluted tubule of the kidney) that is usually regarded as associated with absorptive phenomena …   Useful english dictionary

  • brush border — Projections of microvilli free on the surface of epithelial cells that produce a brush like appearance …   Dictionary of invertebrate zoology

  • brush border — noun Date: 1903 a stria of microvilli on the plasma membrane of an epithelial cell (as in a kidney tubule) that is specialized for absorption …   New Collegiate Dictionary

  • brush border — The densely packed microvilli on the apical surface of, for example, intestinal epithelial cells …   Dictionary of molecular biology

  • brush border — Anat. a dense array of microvilli projecting from the surface of certain epithelial tissues, as the lining of the intestinal tract. [1900 05] * * * …   Universalium

  • brush border — see microvillus …   The new mediacal dictionary

  • border — The part of a surface that forms its outer boundary. SEE ALSO: edge, margin, b.. SYN: margo [TA]. alveolar b. 1. the most occlusal edge of the alveolar bone; 2. SYN: alveolar process of …   Medical dictionary

  • Каемка Щеточная Эпителиальной Ткани (Brush Border) — см. Микроворсинка. Источник: Медицинский словарь …   Медицинские термины

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