Mucosa associated lymphoid tissue
The mucosa lining the alimentary, respiratory, genito-urinary and other surfaces is exposed to antigens. So these areas have rich collec-tion of lymphoid cells
These lymphoid cells are called Peyerâ€™s patches or scattered isolated lymphoid follicles. These are called as Mucosa associated lym-phoid organs (MALT).
Lymphoid tissues in the gut, ie from the adenoids and tonsils up to the follicles of colon are called Gut associated lymphoid tissues (GALT)
Functions of MALT and GALT
1. They contain lymphoid and phagocytic cells and a special cell called M cells
2. Both B and T cells are present
3. Predominant antibody produced is IgA in the mucosal lining. Oth- ers such as IgG, IgM, and IgE are also produced.
4. Ig A antibodies provide first line of defense against infectious agents