
Overview: Outer defense - Diffuse lymphoid tissue
The lamina propria contains both diffuse and nodular lymphoid tissue, aggregations of immune cells, and connective tissue cells that respond to invading microbes. These images show diffuse lymphoid tissue that filters tissue fluid percolating through the connective tissue in which it is located. When located in the lamina propria, as shown here, diffuse lymphoid tissue forms part of MALT (mucosa-associated lymphoid tissue). 200x, 400x

Epithelium
The lamina propria contains both diffuse and nodular lymphoid tissue, aggregations of immune cells and connective tissue cells that respond to invading microbes. These examples show diffuse lymphoid tissue that filters tissue fluid percolating through connective tissue in which it is located. When located in the lamina propria of the gut (left) it forms part of MALT (mucosa-associated lymphoid tissue). 200x, 400x

Lamina propria
The lamina propria contains both diffuse and nodular lymphoid tissue, aggregations of immune cells and connective tissue cells that respond to invading microbes. These examples show diffuse lymphoid tissue that filters tissue fluid percolating through connective tissue in which it is located. When located in the lamina propria of the gut (left) it forms part of MALT (mucosa-associated lymphoid tissue). 200x, 400x

Muscularis mucosae
The lamina propria contains both diffuse and nodular lymphoid tissue, aggregations of immune cells and connective tissue cells that respond to invading microbes. These examples show diffuse lymphoid tissue that filters tissue fluid percolating through connective tissue in which it is located. When located in the lamina propria of the gut (left) it forms part of MALT (mucosa-associated lymphoid tissue). 200x, 400x

Diffuse lymphoid tissue >
Diffuse lymphoid tissue is an unorganized concentration of lymphoid cells in the lamina propria of any organ opening to the exterior. Although lymphocytes predominate, macrophages and plasma cells are also present. Diffuse lymphoid tissue filters tissue fluid of the connective tissue in which it is located and responds by initiating an immune response.

Image source >
This image was taken of a slide from the University of Mississippi collection.