<P> The mucosa - associated lymphoid tissue ( MALT ) , also called mucosa - associated lymphatic tissue , is a diffuse system of small concentrations of lymphoid tissue found in various submucosal membrane sites of the body , such as the gastrointestinal tract , oral passage , nasopharyngeal tract , thyroid , breast , lung , salivary glands , eye , and skin . MALT is populated by lymphocytes such as T cells and B cells , as well as plasma cells and macrophages , each of which is well situated to encounter antigens passing through the mucosal epithelium . In the case of intestinal MALT , M cells are also present , which sample antigen from the lumen and deliver it to the lymphoid tissue . </P>
where are mucosal associated lymphoid tissues present in the human body and why
gastrointestinal tract oral passage nasopharyngeal tract thyroid breast lung salivary glands eye skin