SPLEEN - pediagenosis
Article Update

Thursday, September 24, 2020



The spleen is divided into the white pulp, which includes the periarteriolar lymphoid sheaths (PALS) and functions as a secondary lymphoid tissue, and the macrophagerich red pulp, which is responsible for the removal by phagocytosis of aging erythrocytes, platelets, and some bloodborne pathogens. 


Figure 6.16 Spleen. (a) Lowpower view of human spleen showing red pulp (RP) and lymphoid white pulp (WP). Mallory’s triple stain. (Source: Image courtesy of G. Campbell.) (b) Diagrammatic representation of an area of white pulp surrounded by red pulp. (c) Highpower view of germinal center (GC) and lymphocyte mantle (M) surrounded by marginal zone (MZ) and red pulp (RP). Adjacent to the follicle, an arteriole (A) is surrounded by the periarteriolar lymphoid sheath (PALS) predominantly consisting of Tcells. Note that the marginal zone is present only above the secondary follicle.

The white pulp constitutes circular or elongated areas (Figure 6.16a) within the erythrocytecontaining red pulp, which possesses bloodfilled venous sinusoids (channels) lined with macrophages. As in the lymph node, the T and Bcell areas of the white pulp are segregated (Figure 6.16b). In addition to acting as a very effective blood filter removing effete (old or damaged) cells, the spleen is also important in generating immune responses against any infectious agents present in the blood. Plasmablasts and mature plasma cells are present in the area referred to as the marginal zone extending into the red pulp (Figure 6.16c).

Share with your friends

Give us your opinion

Note: Only a member of this blog may post a comment.

This is just an example, you can fill it later with your own note.