Mucosa: MALT
Mucosa-associated lymphoid tissue (MALT) refers to collections of lymphoid tissue located in the lamina propria throughout the tubular digestive tract. MALT is present either as diffuse cells (left), condensed nodules (middle) or aggregates of nodules (right). MALT consists primarily of B and T lymphocytes, and provides antigen surveillance of tissue fluid to initiate an immune response. 200x, 50x, 10x
Diffuse lymphoid tissue >
Diffuse lymphoid tissue consists of dispersed lymphoid cells (B and T lymphocytes, macrophages and plasma cells) in the lamina propria.
Nodular lymphoid tissue >
Nodular lymphoid tissue consists of tightly packed lymphoid cells that form primary nodules (solid-looking spheres of lymphocytes) or secondary nodules. Secondary nodules are derived from primary nodules and contain a central, pale zone called the germinal center surrounded composed of proliferating lymphocytes. Nodules respond to antigens carried in the tissue fluid.
Nodule aggregate (Peyer’s patch) >
Nodule aggregates (Peyer’s patches) are common in the lamina propria of the ileum on the side opposite the mesentery. They consist of both diffuse and nodular lymphoid tissues.
Image credit >
This image was taken of a slide in the University of Pittsburgh slide collection.
PREVIOUS