Difference between revisions of "Peyer's Patches - Anatomy & Physiology"
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[[Image:LH Ileal Peyer's Patch Diagram.jpg|thumb|250px|right|<p>'''Diagram: Peyer's patch'''</p><sup>©Nottingham Uni 2008</sup>]] | [[Image:LH Ileal Peyer's Patch Diagram.jpg|thumb|250px|right|<p>'''Diagram: Peyer's patch'''</p><sup>©Nottingham Uni 2008</sup>]] | ||
| + | ==Introduction== | ||
<p>''Also called aggregated nodules''</p> | <p>''Also called aggregated nodules''</p> | ||
| − | <p>Peyer’s patches are lymphoid tissues found in the wall of the [[Small Intestine - Anatomy & Physiology|small intestine]]. They are part of the mucosal-associated lymphoid tissues (MALT) and more specifically the gut-associated lymphoid tissue (GALT). Although nodules of lymphatic tissue are found throughout the intestines in the [[Small Intestine - Anatomy & Physiology|small intestine]] larger collections of nodules exist and these are referred to as Peyer’s patches. In many species they act as a primary lymphoid tissue (cattle, sheep , pigs, horses, dogs and rabbits).</p> | + | <p>Peyer’s patches are lymphoid tissues found in the wall of the [[Small Intestine Overview - Anatomy & Physiology|small intestine]]. They are part of the [[Regional Lymphoid Tissue - Anatomy & Physiology|mucosal-associated lymphoid tissues (MALT)]] and more specifically the gut-associated lymphoid tissue (GALT). Although nodules of lymphatic tissue are found throughout the intestines in the [[Small Intestine Overview - Anatomy & Physiology|small intestine]] larger collections of nodules exist and these are referred to as Peyer’s patches. In many species they act as a [[:Category:Primary Lymphoid Tissue|primary lymphoid tissue]] (cattle, sheep , pigs, horses, dogs and rabbits).</p> |
==Development == | ==Development == | ||
<p>In cattle, sheep , pigs, horses and dogs over eighty percent of the patches are found in the [[Ileum - Anatomy & Physiology|ileum]] where they form a continuous structure which is most developed before birth and regresses to the point that in the adult they cannot be detected. The rest of the patches are found in the [[jejunum - Anatomy & Physiology|jejunum]] and are isolated from each other, however these patches last throughout adult life.</p><p> In rabbits and rodents the patches are randomly located along both the [[Ileum - Anatomy & Physiology|ileum]] and [[jejunum - Anatomy & Physiology|jejunum]] and persist throughout life.</p> | <p>In cattle, sheep , pigs, horses and dogs over eighty percent of the patches are found in the [[Ileum - Anatomy & Physiology|ileum]] where they form a continuous structure which is most developed before birth and regresses to the point that in the adult they cannot be detected. The rest of the patches are found in the [[jejunum - Anatomy & Physiology|jejunum]] and are isolated from each other, however these patches last throughout adult life.</p><p> In rabbits and rodents the patches are randomly located along both the [[Ileum - Anatomy & Physiology|ileum]] and [[jejunum - Anatomy & Physiology|jejunum]] and persist throughout life.</p> | ||
==Structure== | ==Structure== | ||
| − | Peyer’s patches are located in the lamina propria and submucosa of [[Small Intestine - Anatomy & Physiology|small intestine]] and may be distinguishable by the lack of villi covering them. The patches are regions of concentrated [[Lymphocytes | + | Peyer’s patches are located in the lamina propria and submucosa of [[Small Intestine Overview - Anatomy & Physiology|small intestine]] and may be distinguishable by the lack of villi covering them. The patches are regions of concentrated [[Lymphocytes#B cells|B lymphocyte]] follicles covered in a ‘dome’ of a specialised follicle associated epithelium (FAE) which consists of follicle associated enterocytes and M (microfold or multifold) cells. |
===M cells=== | ===M cells=== | ||
M cells transport antigens from the intestinal lumen to the lymphocytes. Their luminal surface is folded and takes up antigens from the intestine via endocytosis and transports them to the extracellular space on their basal surface where the antigen is processed by antigen presenting cells. | M cells transport antigens from the intestinal lumen to the lymphocytes. Their luminal surface is folded and takes up antigens from the intestine via endocytosis and transports them to the extracellular space on their basal surface where the antigen is processed by antigen presenting cells. | ||
| Line 27: | Line 18: | ||
==Function== | ==Function== | ||
| − | Peyer’s patches have a similar role to that of the avian [[Bursa of Fabricius - Anatomy & Physiology|bursa of Fabricius]] in maturing and differentiation immature B lymphocytes. Antigens are presented to the [[Lymphocytes | + | Peyer’s patches have a similar role to that of the avian [[Bursa of Fabricius - Anatomy & Physiology|bursa of Fabricius]] in maturing and differentiation immature B lymphocytes. Antigens are presented to the [[Lymphocytes#B cells|B lymphocytes]] in the follicle which causes the [[Lymphocytes#B cells|B cells]] to become committed to [[Immunoglobulin A|IgA]] synthesis. In ruminants and pigs Peyer's patches in the [[Ileum - Anatomy & Physiology|ileum]] have a primary lympoid fuction while those in the [[Jejunum - Anatomy & Physiology|jejenum]] have a secondary lymphoid function. |
==In pathology== | ==In pathology== | ||
| − | * | + | *[[Salmonellosis|Septicaemic salmonellosis]] affects the Peyer's patches |
| − | + | *[[Bovine Viral Diarrhoea Virus|Bovine Viral Diarrhoea disease]] causes ulcers to form over the patches | |
| − | *[[ | + | *Infected by mycobacteria in [[Johne's Disease|Johnes disease]] |
| − | *Infected by mycobacteria in [[ | ||
*[[Yersinia]] enter the intestinal mucosa via M cells | *[[Yersinia]] enter the intestinal mucosa via M cells | ||
| + | |||
| + | <br><br> | ||
| + | {{Jim Bee 2007}} | ||
| + | |||
| + | ==Webinars== | ||
| + | <rss max="10" highlight="none">https://www.thewebinarvet.com/gastroenterology-and-nutrition/webinars/feed</rss> | ||
| + | |||
| + | [[Category:Mucosal Associated Lymphoid Tissue]] | ||
Latest revision as of 14:13, 5 January 2023
Introduction
Also called aggregated nodules
Peyer’s patches are lymphoid tissues found in the wall of the small intestine. They are part of the mucosal-associated lymphoid tissues (MALT) and more specifically the gut-associated lymphoid tissue (GALT). Although nodules of lymphatic tissue are found throughout the intestines in the small intestine larger collections of nodules exist and these are referred to as Peyer’s patches. In many species they act as a primary lymphoid tissue (cattle, sheep , pigs, horses, dogs and rabbits).
Development
In cattle, sheep , pigs, horses and dogs over eighty percent of the patches are found in the ileum where they form a continuous structure which is most developed before birth and regresses to the point that in the adult they cannot be detected. The rest of the patches are found in the jejunum and are isolated from each other, however these patches last throughout adult life.
In rabbits and rodents the patches are randomly located along both the ileum and jejunum and persist throughout life.
Structure
Peyer’s patches are located in the lamina propria and submucosa of small intestine and may be distinguishable by the lack of villi covering them. The patches are regions of concentrated B lymphocyte follicles covered in a ‘dome’ of a specialised follicle associated epithelium (FAE) which consists of follicle associated enterocytes and M (microfold or multifold) cells.
M cells
M cells transport antigens from the intestinal lumen to the lymphocytes. Their luminal surface is folded and takes up antigens from the intestine via endocytosis and transports them to the extracellular space on their basal surface where the antigen is processed by antigen presenting cells.
Histology
Intetsine w/Peyer's patch
©RVC 2008
Peyer's patch
©RVC 2008
Peyer's patches
Courtesy of BioMed Archive
Function
Peyer’s patches have a similar role to that of the avian bursa of Fabricius in maturing and differentiation immature B lymphocytes. Antigens are presented to the B lymphocytes in the follicle which causes the B cells to become committed to IgA synthesis. In ruminants and pigs Peyer's patches in the ileum have a primary lympoid fuction while those in the jejenum have a secondary lymphoid function.
In pathology
- Septicaemic salmonellosis affects the Peyer's patches
- Bovine Viral Diarrhoea disease causes ulcers to form over the patches
- Infected by mycobacteria in Johnes disease
- Yersinia enter the intestinal mucosa via M cells
|
Originally funded by the RVC Jim Bee Award 2007 |
Webinars
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