Gut-associated lymphoid tissue (GALT)
Loosely organized, nonencapsulated clusters of LYMPH tissue beneath the epithelium (tissue that forms the mucous lining) of the gastrointestinal tract from the ESOPHAGUS to the COLON. T-cell lymphocytes, Bcell lymphocytes, and macrophages primarily inhabit GALT. The role of GALT is to block NORMAL FLORA BACTERIA (bacteria that are normally present in the gastrointestinal tract to aid digestion) from penetrating into other tissues or the BLOOD circulation. GALT also helps prevent gastrointestinal viruses from causing INFECTION. The presence of GALT in the lining of the STOMACH increases with aging. GALT also includes the small, nodelike lymphoid structures called PEYER’S PATCHES that pepper the SMALL INTESTINE. Peyer’s patches intensify the presence of the IMMUNE SYSTEM and are the sites of much ANTIBODY activity from B-lymphocytes.
See also LYMPH NODE; LYMPHOCYTE; MACROPHAGE; MUCOSA-ASSOCIATED LYMPHOID TISSUE (MALT); NOSEASSOCIATED LYMPHOID TISSUE (NALT); PATHOGEN; PHAGOCYTE; PHAGOCYTOSIS; SKIN-ASSOCIATED LYMPHOID TISSUE (SALT); VIRUS.
