How is spleen white pulp

• 25% of the spleen, the white pulp is responsible for the immunological function of the spleen. It comprises the lymphoid compartment of the spleen, and contains: • Periarteriolar lymphatic sheaths (PALS): tightly packed T cells arranged in cylindrical sheaths around central arterioles (may expand to form nodule of B cells developing into germinal centers) • Lymphoid follicles: spherical aggregations of B cells scattered throughout the PALS