Gut-associated lymphoid tissue
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The digestive tract's immune system is often referred to as gut-associated lymphoid tissue (GALT) and works to protect the body from invasion. GALT is an example of mucosa-associated lymphoid tissue.
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[edit] Function
About 70% of the body's immune system is found in the digestive tract. The GALT is made up of several types of lymphoid tissue that produce and store immune cells that carry out attacks and defend against pathogens.
New research indicates that GALT may continue to be a major site of HIV activity, even if drug treatment has reduced HIV count in the peripheral blood.[citation needed]
[edit] Components
Lymphoid tissue in the gut is comprised of the following :
- Tonsils (Waldeyer's ring)
- Adenoids (Pharyngeal tonsils)
- Peyer's patches
- Lymphoid aggregates in the appendix and large intestine
- Lymphoid tissue accumulating with age in the stomach
- Small lymphoid aggregates in the oesophagus
- Diffusely distributed lymphoid cells and plasma cells in the lamina propria of the gut
[edit] Additional images
 Lymphatics of colon. |
 Section of the human esophagus. |
 Transverse section of human vermiform process. X 20. |
 Section of mucous membrane of human rectum. X 60. |
[edit] External links
- Histology at BU 12502loa - "Digestive System: Alimentary Canal: colon, taenia coli"
- Histology at BU 11102loa - "Digestive System: Alimentary Canal: esophageal/stomach junction"
| Anatomy of torso, digestive system: Gastrointestinal tract |
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| Upper gastrointestinal tract Mouth • Pharynx (nasopharynx, oropharynx, hypopharynx) • Esophagus • Crop • Stomach (rugae, gastric pits, cardia/gland, fundus/gland, pylorus/gland, pyloric antrum) Lower gastrointestinal tract Large intestine: Cecum • Colon (ascending colon, transverse colon, descending colon, sigmoid colon) • Rectum (Houston valve, rectal ampulla, pectinate line) • Anal canal (anal valves, anal sinuses, anal columns) Anus: Sphincter ani internus muscle • Sphincter ani externus muscle GALT: Peyer's patches • M cells intestinal villus • crypts of Lieberkühn • circular folds • taenia coli • haustra • epiploic appendix |
Bone marrow | Thymus (Hassall's corpuscles) | Spleen (White pulp, Periarteriolar lymphoid sheaths, Marginal zone, Red pulp) | Tonsils/Waldeyer's tonsillar ring (Palatine, Lingual, Adenoid)
Mucosa-associated lymphoid tissue: Gut-associated lymphoid tissue | Peyer's patches
Lymph nodes: Subcapsular sinus | Paracortex | Lymph vessels
Lymph | Lymphocytes | High endothelial venules | Immune system
