Spleen is the largest of the lymphoid organs. It has a capsule from which descent trabaculae dividing the organ into several intercon-nected compartments. Spleen is made up of white pulp and red pulp
The spleenic artery travels along the trabaculae. On entering the spleen the artery divides into arterioles which are surrounded by lym-phoid tissues. This part is called white pulp. White pulp is rich in lym-phoid cells.
It is called red pulp because of the red blood cells. Macroph-ages also are present in this area
Functions of spleen
1. The spleen serves as the grave yard for red blood cells
2. The white pulp is rich in T cells and B cells
3. The T cells are seen peripherally and the B cells are seen centrally
4. After an antigenic stimulus the germinal center containing large num-ber of B cells and plasma cells appear in the periarteriolar areas and almost replace T cells.