Editing Duodenum (section)

{{Short description|First section of the small intestine}}
{{for|the song|Duodenum (song)}}
{{Infobox anatomy
| Name        = Duodenum
| Latin       = duodenum
| Image       = Tractus intestinalis duodenum.svg
| Caption     = Image of the [[Human gastrointestinal tract|gastrointestinal tract]], with the duodenum highlighted.
| Width       =
| Image2      = Duodenumanatomy.jpg
| Caption2    = Diagram of the human duodenum with major parts labelled
| Precursor   = [[Foregut]] (1st and 2nd parts), [[midgut]] (3rd and 4th part)
| System      = [[Digestion|Digestive system]]
| PartOf      = [[Small intestine]]
| Pronunciation = {{IPAc-en|ˌ|dj|uː|ə|ˈ|d|iː|n|ə|m}}, {{IPAc-en|usalso|dj|u|ˈ|ɒ|d|ɪ|n|ə|m}}<ref>{{cite EPD|18}}</ref>
| Artery      = [[Inferior pancreaticoduodenal artery]], [[superior pancreaticoduodenal artery]]
| Vein        = [[Pancreaticoduodenal veins]]
| Nerve       = [[Celiac ganglia]], [[vagus]]<ref>{{cite book| title= Essentials of Human Physiology| first= Thomas M. |last= Nosek| chapter=Section 6/6ch2/s6ch2_30 |chapter-url=http://humanphysiology.tuars.com/program/section6/6ch2/s6ch2_30.htm |archive-url=https://web.archive.org/web/20160324124828/http://humanphysiology.tuars.com/program/section6/6ch2/s6ch2_30.htm|archive-date=2016-03-24}}</ref>
| Lymph       =
}}
{{Gastrointestinal tract sidebar}}
The '''duodenum''' is the first section of the [[small intestine]]<ref name="National Cancer Institute">{{cite web | title=NCI Dictionary of Cancer Terms | website=National Cancer Institute | url=https://www.cancer.gov/publications/dictionaries/cancer-terms | access-date=2022-06-07 | quote=The first part of the small intestine. It connects to the stomach. The duodenum helps to further digest food coming from the stomach. It absorbs nutrients (vitamins, minerals, carbohydrates, fats, proteins) and water from food so they can be used by the body.}}</ref> in most [[vertebrates]], including [[mammals]], [[reptiles]], and [[birds]]. In mammals, it may be the principal site for [[iron]] absorption.
The duodenum precedes the [[jejunum]] and [[ileum]] and is the shortest part of the small intestine.

In humans, the duodenum is a hollow jointed tube about {{convert|25–38|cm|4=0|abbr=off}} long connecting the [[stomach]] to the jejunum, the middle part of the small intestine.<ref name="MedlinePlus">{{cite web | title=Duodenum: MedlinePlus Medical Encyclopedia | website=MedlinePlus | url=https://medlineplus.gov/ency/article/002347.htm | access-date=2022-06-07 | quote=It is located between the stomach and the middle part of the small intestine. After foods mix with stomach acid, they move into the duodenum, where they mix with bile from the gallbladder and digestive juices from the pancreas.}}</ref><ref name="Nolan 2002 pp. 247–259">{{cite book | last=Nolan | first=D. J. | title=Radiological Imaging of the Small Intestine | chapter=Radiology of the Duodenum | series=Medical Radiology | publisher=Springer Berlin Heidelberg | publication-place=Berlin, Heidelberg | year=2002 | isbn=978-3-642-62993-8 | issn=0942-5373 | doi=10.1007/978-3-642-56231-0_6 | pages=247–259 | quote=duodenum is a C-shaped hollow organ forming an incomplete circle around the head of the pancreas. ...it is normally examined as part of the upper gastrointestinal tract. | chapter-url=https://link.springer.com/chapter/10.1007/978-3-642-56231-0_6}}</ref> It begins with the [[duodenal bulb]], and ends at the [[duodenojejunal flexure]] marked by the  [[suspensory muscle of duodenum]].<ref>{{cite journal |author=van Gijn J |title=Treitz and his ligament. |journal=Ned. Tijdschr. Geneeskd. |volume=155 |issue=8 |year=2011 |pmid=21557825 |author2=Gijselhart JP |pages=A2879}}</ref> The duodenum can be divided into four parts: the first (superior), the second (descending), the third (transverse) and the fourth (ascending) parts.<ref name="Nolan 2002 pp. 247–259"/>