Jejunum


Jejunum

Infobox Anatomy
Name = PAGENAME
Latin =
GraySubject = 248
GrayPage = 1170


Caption = Small intestine


Caption2 = Superior and inferior duodenal fossæ.
Precursor = midgut
System =
Artery = jejunal arteries
Vein = jejunal veins
Nerve = celiac ganglia, vagus [GeorgiaPhysiology|6/6ch2/s6ch2_30]
Lymph =
MeshName = Jejunum
MeshNumber = A03.556.124.684.500
DorlandsPre =
DorlandsSuf =
In anatomy of the digestive system, the jejunum is the central of the three divisions of the small intestine and lies between the duodenum and the ileum. The change from the duodenum to the jejunum is usually defined as the ligament of Treitz.

In adult humans, the small intestine is usually between 5.5-6m long, 2.5m of which is the jejunum.

The pH in the jejunum is usually between 7 and 8 (neutral or slightly alkaline).

The jejunum and the ileum are suspended by mesentery which gives the bowel great mobility within the abdomen. It also contains muscles to help move the food along.

Internal structure

The inner surface of the jejunum, its mucous membrane, is covered in projections called villi, which increase the surface area of tissue available to absorb nutrients from the gut contents. The epithelial cells which line these villi possess even larger numbers of microvilli. The transport of nutrients across epithelial cells through the jejunum and ileum includes the passive transport of sugar fructose and the active transport of amino acids, small peptides, vitamins, and most glucose. The villi in the jejunum are much longer than in the duodenum or ileum.

The jejunum contains very few Brunner's glands (found in the duodenum) or Peyer's patches (found in the ileum). Instead, it has many large circular folds in its submucosa called plicae circulares which increase the surface area for nutrient absorption.

Etymology

"Jejunum" is derived from the adjective "jejune", which means "fasting" or "hungry" in Early Modern English.It was so called because this portion of the intestine was found "empty" following death Fact|date=April 2007 [Latin: jejunus, fasting; barren]


=Additional

References

External links

* [http://www.gastrolab.net/bb12je.htm Gastrolab.net:The Jejunum]
* [http://www.thehealthnews.org/news/06/08/01/Peyers.Patches.html Peyer's patches]
* - "Abdominal Cavity: The Jejunum and the Ileum"
*


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Look at other dictionaries:

  • jéjunum — [ ʒeʒynɔm ] n. m. • v. 1370; lat. méd. jejunum intestinum « intestin à jeun », à cause du peu de matières qu il contient ♦ Anat. Premier segment du jéjuno iléon, faisant suite au duodénum. Adj. JÉJUNAL, ALE, AUX . ● jéjunum nom masculin (bas… …   Encyclopédie Universelle

  • Jejunum — Jéjunum Intestin grêle En anatomie du système digestif, le jéjunum (de l adjectif latin jejune, qui signifie jeûne ou affamé ) est la partie centrale des trois divisions de l intestin grêle, en aval du duodénum et en amont de l iléon. Chez l …   Wikipédia en Français

  • Jejunum — Je*ju num, n. [NL., fr. L. jejunus empty, dry.] (Anat.) The middle division of the small intestine, between the duodenum and ileum; so called because usually found empty after death. [1913 Webster] …   The Collaborative International Dictionary of English

  • Jejūnum — (lat.), Leerdarm, s. Darm, S. 520 …   Meyers Großes Konversations-Lexikon

  • jejunum — late 14c., from L. ieiunum, neut. of ieiunus (see JEJUNE (Cf. jejune)). Translating Gk. nestis (Galen). So called because it typically is found empty during dissections, perhaps because it would tend to drain in a body laid on its back …   Etymology dictionary

  • jejunum — jejúnum m DEFINICIJA anat. dio tankog crijeva između dvanaesnika i ileuma ETIMOLOGIJA lat. ieiunum …   Hrvatski jezični portal

  • jejunum — [jē jo͞o′nəm, jəjo͞o′nəm] n. pl. jejuna [jē jo͞o′nə, jə jo͞o′nə] [ML < neut. of L jejunus, empty: it was formerly thought to be empty after death] the middle part of the small intestine, between the duodenum and the ileum: see INTESTINE… …   English World dictionary

  • Jejunum — Das Jejunum (zu deutsch „Leerdarm“) ist einer der drei Abschnitte des Dünndarms. Er schließt sich an das Duodenum („Zwölffingerdarm“) an und geht in das Ileum über. Er ist bei einem erwachsenen Menschen bis zu zwei Meter lang. Seinen deutschen… …   Deutsch Wikipedia

  • Jéjunum — Intestin grêle Le jéjunum (de l adjectif latin jejune, qui signifie « jeûne » ou « affamé ») est la partie centrale de l intestin grêle, en aval du duodénum et en amont de l iléon. Chez l Homme adulte, il mesure en général de… …   Wikipédia en Français

  • Jejunum — Part of the small intestine. It is half way down the small intestine between its duodenum and ileum sections. The term jejunum derives from the Latin jejunus, which means empty of food, meager, or hungry. The ancient Greeks noticed at death that… …   Medical dictionary


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