Changes

==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 - WikiBlood#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.  

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#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.

==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 - WikiBlood#B cells|B lymphocytes]] in the follicle which causes the [[Lymphocytes - WikiBlood#B cells|B cells]] to become committed to [[Immunoglobulin A - WikiBlood|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.

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 - WikiBlood|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==