Mucosal - Associated Lymphoid Tissue (MALT):
- It is non-encapsulated clusters of lymphoid tissue with immune function is the "mucosal immune system".
- It is common around the membrane lining the respiratory, digestive and urogenital tracts (gateways to the body for involving organisms)
- The MALT of the gut is called "Gut-Associated lymphoid tissues"(GALT).
- It includes payer's patches and focal accumulations of lymphocytes in the lamina propria.
- The MALT filters out antigens that enter in air and food (or) come from microorganisms growing in the intestines.
- The antigen activated B-Lymphocytes of the bodies first line defense against infection by microorganisms.
- These B-cells also make Ig.E as a main response to helminthes.
- The mucosal layer of the alimentary canal, respiratory and urinogential tracts is provided with dispersed groups of lymphoid tissues known as MALT.
These tissues are usually without a capsule (uncapsulated). In human beings the payers patches, the tonsils and appendix are good examples of lymphoid tissues found in the mucosal layer of the alimentary canal. Hence these are also referred to as GALT (Gut Associated Lymphoid Tissue).