Greater omentum
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2008-06-11T09:53:04Z
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Adding link to the french version of the article (Épipoloon)
{{Infobox Anatomy |
Name = Greater omentum |
Latin = omentum majus |
GraySubject = 246 |
GrayPage = 1157 |
Image = Gray1035.png |
Caption = Vertical disposition of the [[peritoneum]]. Main cavity, red; omental bursa, blue. (Greater omentum labeled at left.) |
Image2 = Gray987.png |
Caption2 = Diagrams to illustrate two stages in the development of the digestive tube and its mesentery. The arrow indicates the entrance to the bursa omentalis. |
System = |
Precursor = [[Dorsal mesentery]] |
MeshName = Omentum |
MeshNumber = A01.047.025.600.573 |
}}
The '''greater omentum''' (also the '''great omentum''', '''omentum majus ''', '''gastrocolic omentum''', or '''epiploön''') is a large fold of [[peritoneum]] that hangs down from the stomach, and extends from the [[stomach]] to the posterior [[abdominal wall]] after associating with the [[transverse colon]].
==Structure==
The greater omentum is the largest peritoneal fold. It consists of a double sheet of [[peritoneum]], folded on itself so that it is made up of four layers.
The two layers which descend from the stomach and commencement of the [[duodenum]] pass in front of the [[small intestine]]s, sometimes as low down as the [[pelvis]]; they then turn upon themselves, and ascend again as far as the [[transverse colon]], where they separate and enclose that part of the intestine.
These individual layers may be easily demonstrated in the young subject, but in the adult they are more or less inseparably blended.
The left border of the greater omentum is continuous with the [[gastrolienal ligament]]; its right border extends as far as the commencement of the [[duodenum]].
The greater omentum is usually thin, presents a [[cribriform]] appearance, and always contains some [[adipose tissue]], which in obese people accumulates in considerable quantity.
Between its two anterior layers, a short distance from the greater curvature of the stomach, is the [[anastomosis]] between the right and left [[gastroepiploic artery|gastroepiploic vessels]].
===Subdivisions===
The greater omentum is often defined to encompass a variety of structures. Most sources include the following three:<ref name="isbn0-7817-3639-0">{{cite book |author=Dalley, Arthur F.; Moore, Keith L. |title=Clinically oriented anatomy |publisher=Lippincott Williams & Wilkins |location=Hagerstwon, MD |year=2006 |pages=237 |isbn=0-7817-3639-0 |oclc= |doi=}}</ref><ref>[http://anatomy.med.umich.edu/gastrointestinal_system/stomach_tables.html Anatomy Tables - Stomach & Spleen<!-- Bot generated title -->]</ref>
* [[Gastrocolic ligament]] - to [[transverse colon]] (occasionally on its own considered synonymous with "greater omentum"<ref name="isbn0-7817-3639-0"> </ref>)
* [[Gastrosplenic ligament]] - to [[spleen]]
* [[Gastrophrenic ligament]] - to [[thoracic diaphragm]]
The [[splenorenal ligament]] (from the left [[kidney]] to the [[spleen]]) is occasionally considered part of the greater omentum.<ref>{{cite book |author=Kyung Won, PhD. Chung |title=Gross Anatomy (Board Review) |publisher=Lippincott Williams & Wilkins |location=Hagerstwon, MD |year=2005 |pages=205 |isbn=0-7817-5309-0 |oclc= |doi=}}</ref><ref name="titleModule - Peritoneal Cavity Development">{{cite web |url=http://anatomy.med.umich.edu/modules/peritoneal_dev_module/peritoneal_04.html |title=Module - Peritoneal Cavity Development |accessdate=2007-12-01 |format= |work=}}</ref>
==Development==
The greater omentum develops from the [[dorsal mesentery]] that connects the [[stomach]] to the posterior abdominal wall. During stomach development, the stomach undergoes its first 90° rotation along the axis of the embryo, so that posterior structures are moved to the left and structures anterior to the stomach are shifted to the right. As a result, the dorsal mesentery folds over on itself, forming a pouch with its blind end on the left side of the embryo. A second approximately 90° rotation of the stomach, this time in the [[frontal plane]], moves structures inferior if they were originally to the left of the stomach, and superior if they were originally to the stomach's right. Consequently, the blind-ended sac (also called the [[lesser sac]]) formed by the dorsal mesentery is brought inferiorly, where it assumes its final position as the greater omentum. It grows to the point that it covers the majority of the small and large intestine.
==Additional images==
<gallery>
Image:Gray532.png|The celiac artery and its branches; the liver has been raised, and the lesser omentum and anterior layer of the greater omentum removed.
Image:Gray989.png|Schematic figure of the bursa omentalis, etc. Human embryo of eight weeks.
Image:Gray990.png|Diagrams to illustrate the development of the greater omentum and transverse mesocolon.
</gallery>
==See also==
* [[Peritoneum]]
* [[Lesser omentum]]
* [[Right gastroepiploic vein]]
* [[Omental cake]]
==References==
<references/>
==External links==
* {{SUNYAnatomyFigs|37|03|07}}
* {{SUNYAnatomyFigs|37|05|12}}
* {{SUNYAnatomyLabs|37|07|01|00}}
* [http://faculty.southwest.tn.edu/rburkett/Digest32.jpg Diagram at Tn.edu]
* {{WaynesburgAnatomicModel|digirep/greateromentum}}
{{Peritoneum}}
[[Category:Abdomen]]
[[de:Omentum majus]]
[[fr:Épiploon]]
[[it:Grande omento]]
[[la:Omentum maius]]
[[pl:Sieć większa]]
[[pt:Omento maior]]