Editing Jejunum (section)

{{Short description|Part of the small intestine}}
{{Distinguish|duodenum}}
{{Infobox anatomy
| Name        = Jejunum
| Latin       = jejunum
| Image       = Illu small intestine.jpg
| Caption     = Small intestine
| Width       = 
| Image2      = Gray1041.png
| Caption2    = Superior and inferior duodenal fossæ.
| Precursor   = [[Midgut]]
| Artery      = [[Jejunal arteries]]
| Vein        = [[Jejunal 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       = 
| PartOf      = [[Small intestine]]
| System      = [[Digestion|Digestive system]]
| Pronunciation = {{IPAc-en|dʒ|ᵻ|ˈ|dʒ|uː|n|əm}} {{respell|jij|OO|nəm}}<ref>''[[OED]]'' 2nd edition, 1989.</ref><ref>[http://www.merriam-webster.com/dictionary/jejunum Entry "jejunum"] in ''[http://www.merriam-webster.com/ Merriam-Webster Online Dictionary]''.</ref>
}}
{{Gastrointestinal tract sidebar}}
The '''jejunum''' is the second part of the [[small intestine]] in [[human]]s and most [[higher vertebrates]], including [[mammals]], [[reptiles]], and [[birds]].  Its lining is specialized for the absorption by [[enterocytes]] of small nutrient [[molecule]]s which have been previously digested by [[enzymes]] in the [[duodenum]].

The jejunum lies between the [[duodenum]] and the [[ileum]] and is considered to start at the [[suspensory muscle of the duodenum]], a location called the [[duodenojejunal flexure]].<ref name=GRAYS2005 /> The division between the jejunum and ileum is not anatomically distinct.<ref name=WHEATERS2006>{{cite book|last=Deakin|first=Barbara Young |display-authors=etal |title=Wheater's functional histology : a text and colour atlas|date=2006|publisher=Churchill Livingstone/Elsevier<!--|location=[Edinburgh?]-->|isbn=978-0-443-068-508|page=263|edition=5th}}</ref> In adult [[human]]s, the small intestine is usually {{convert|6|-|7|m|ft|abbr=on}} long (post mortem), about two-fifths of which (about {{convert|2.5|m|ft|abbr=on}}) is the jejunum.<ref name=GRAYS2005>{{cite book|last=Drake|first=Richard L.|title=Gray's anatomy for students|year=2005|publisher=Elsevier/Churchill Livingstone|location=Philadelphia|isbn=978-0-8089-2306-0|author2=Vogl, Wayne |author3=Tibbitts, Adam W. M. Mitchell  |author4=illustrations by Richard |author5= Richardson, Paul |pages=273–275}}</ref>