Editing Stomach (section)

===Microanatomy===
====Wall====
{{Main article|Gastrointestinal wall}}
[[Image:Gastrointestinal wall of human stomach hariadhi.svg|thumb|right|The gastrointestinal wall of the human stomach]]
[[File:Layers of the GI Tract english.svg|thumb|Layers of the gastrointestinal wall of which the stomach is a dilated part]]

Like the other parts of the [[gastrointestinal wall]], the human stomach wall from inner to outer, consists of a [[mucosa]], [[submucosa]], [[muscular layer]], [[subserosa]] and [[serosa]].<ref>{{cite web|title=University of Rochester medical center|url=https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=34&contentid=17785-1|date=2020|access-date=2021-12-19|archive-date=2021-11-19|archive-url=https://web.archive.org/web/20211119050031/https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=34&contentid=17785-1|url-status=dead}}</ref>

The inner part of the stomach wall is the [[gastric mucosa]] a mucous membrane that forms the lining of the stomach. the membrane consists of an outer layer of [[columnar epithelium]], a [[lamina propria]], and a thin layer of [[smooth muscle]] called the [[muscularis mucosa]]. Beneath the mucosa lies the [[submucosa]], consisting of [[fibrous connective tissue]].<ref>{{Cite web|title=Stomach histology|url=https://www.kenhub.com/en/library/anatomy/stomach-histology|access-date=2021-01-09|website=Kenhub|language=en}}</ref> [[Meissner's plexus]] is in this layer interior to the oblique muscle layer.<ref>{{Cite book|title=Gastrointestinal physiology : development, principles and mechanisms of regulation|last=Welcome, Menizibeya Osain|publisher=Springer|year=2018|isbn=978-3-319-91056-7|location=Cham, Switzerland|pages=628|oclc=1042217248}}</ref>

Outside of the submucosa lies the muscular layer. It consists of three layers of muscular fibres, with fibres lying at angles to each other. These are the inner oblique, middle circular, and outer longitudinal layers.<ref>{{Cite web |date=2018-07-22 |title=22.5C: Muscularis |url=https://med.libretexts.org/Bookshelves/Anatomy_and_Physiology/Anatomy_and_Physiology_(Boundless)/22%3A_Digestive_System/22.05%3A_Layers_of_the_Alimentary_Canal/22.5C%3A_Muscularis |access-date=2024-02-09 |website=Medicine LibreTexts |language=en}}</ref> The presence of the inner oblique layer is distinct from other parts of the gastrointestinal tract, which do not possess this layer.<ref>{{Cite web|title=SIU SOM Histology GI|url=http://www.siumed.edu/~dking2/erg/stomach.htm|access-date=2021-01-09|website=www.siumed.edu|archive-date=2021-01-11|archive-url=https://web.archive.org/web/20210111015056/http://www.siumed.edu/~dking2/erg/stomach.htm|url-status=dead}}</ref> The stomach contains the thickest muscular layer consisting of three layers, thus maximum peristalsis occurs here.
* The ''inner oblique layer:'' This layer is responsible for creating the motion that churns and physically breaks down the food. It is the only layer of the three which is not seen in other parts of the [[digestive system]]. The antrum has thicker skin cells in its walls and performs more forceful contractions than the fundus.
* The ''middle circular layer:'' At this layer, the [[pylorus]] is surrounded by a thick circular muscular wall, which is normally tonically constricted, forming a functional (if not anatomically discrete) [[pyloric sphincter]], which controls the movement of [[chyme]] into the [[duodenum]]. This layer is concentric to the [[Anatomical terms of location#Axes|longitudinal axis]] of the stomach.
* The [[myenteric plexus]] (Auerbach's plexus) is found between the outer longitudinal and the middle circular layer and is responsible for the innervation of both (causing [[peristalsis]] and mixing).

The ''outer longitudinal layer'' is responsible for moving the semi-digested food towards the pylorus of the stomach through muscular shortening.

To the outside of the muscular layer lies a [[serosa]], consisting of layers of connective tissue continuous with the [[peritoneum]].

Smooth mucosa along the inside of the lesser curvature forms a passageway - the '''gastric canal'''  that fast-tracks liquids entering the stomach, to the pylorus.<ref name=Elsevier>{{citation |title=Gray's Anatomy |url=https://www.uk.elsevierhealth.com/grays-anatomy-9780702077050.html |publisher=Elsevier |edition=42nd |pages=1160–1163 |author-first=Susan |author-last=Standring}}</ref>

====Glands====
{{Main article|Gastric glands}}
[[File:Illu_stomach_layers.jpg|thumb|Diagram showing gastric pits (13) gastric glands (12) lamina propria (10) epithelium (11)]]
[[File:Histology of normal fundic mucosa.png|thumb|Histology of normal fundic mucosa. Fundic glands are simple, branched tubular glands that extend from the bottom of the gastric pits to the muscularis mucosae; the more distinctive cells are parietal cells. H&E stain.]]
[[File:Histology of normal antral mucosa.png|thumb|Histology of normal antral mucosa. Antral mucosa is formed by branched coiled tubular glands lined by secretory cells similar in appearance to the surface mucous cells. H&E stain.]]
The mucosa lining the stomach is lined with [[gastric pit]]s, which receive [[gastric juice]], secreted by between 2 and 7 [[gastric glands]].{{citation needed|date=May 2020}} Gastric juice is an acidic fluid containing [[hydrochloric acid]] and digestive enzymes.<ref>{{Cite web |date=21 August 2009 |title=How does the Stomach Work? |url=https://www.ncbi.nlm.nih.gov/books/NBK279304/#:~:text=Gastric%20juice%3A%20Acid%2C%20salts%20and%20enzymes&text=These%20glands%20make%20digestive%20enzymes,juice%20are%20made%20each%20day. |access-date=16 June 2024 |website=National Institute of Health: National Library of Medicine |publisher=Institute for Quality and Efficiency in Health Care (IQWiG).}}</ref> The glands contains a number of cells, with the function of the glands changing depending on their position within the stomach.{{citation needed|date=May 2020}}

Within the body and fundus of the stomach lie the ''fundic glands''. In general, these glands are lined by column-shaped cells that secrete a protective layer of [[mucus]] and [[bicarbonate]]. Additional cells present include [[parietal cell]]s that secrete hydrochloric acid and [[intrinsic factor]], [[Gastric chief cell|chief cell]]s that secrete [[pepsinogen]] (this is a precursor to pepsin- the highly acidic environment converts the pepsinogen to pepsin), and neuroendocrine cells that secrete [[serotonin]].<ref name=Dorland777/>{{citation needed|date=May 2020}}

Glands differ where the stomach meets the esophagus and near the pylorus.<ref>{{Cite journal|last1=Gallego-Huidobro|first1=J|last2=Pastor|first2=L M|date=April 1996|title=Histology of the mucosa of the oesophagogastric junction and the stomach in adult Rana perezi.|journal=Journal of Anatomy|volume=188|issue=Pt 2|pages=439–444|issn=0021-8782|pmc=1167580|pmid=8621343}}</ref> Near the [[gastroesophageal junction]] lie ''cardiac glands'', which primarily secrete mucus.<ref name=Dorland777>{{cite book|last1=Dorland's|title=Dorland's Illustrated Medical Dictionary|date=2012|publisher=Elsevier|isbn=978-1-4160-6257-8|page=777|edition=32nd}}</ref> They are fewer in number than the other gastric glands and are more shallowly positioned in the mucosa. There are two kinds - either simple [[tubular gland]]s with short ducts  or [[compound racemose glands|compound racemose]] resembling the [[duodenal]] [[Brunner's glands]].{{citation needed|date=October 2019}} Near the pylorus lie ''pyloric glands'' located in the antrum of the pylorus. They secrete mucus, as well as [[gastrin]] produced by their [[G cells]].<ref>{{cite book|last1=Dorland's|title=Dorland's Illustrated Medical Dictionary|date=2012|publisher=Elsevier|isbn=978-1-4160-6257-8|page=762|edition=32nd}}</ref>{{citation needed|date=May 2020}}