Secondary lymphatic nodule in the spleen (human)

Stain: Trichrome (Goldner). A: Survey of a follicle in the spleen. B: a higher magnification of a similar section shows part of a lymphatic nodule (follicle, white pulp) with cross-sections of the central artery (6). (1) germinal centre (filled with reticular cells, B-memory lymphocytes and macrophages). (2) mantle layer (mainly nave B lymphocytes). (3) marginal zone. (4) perilymphoid zone with sinuses (not sinusoids) apposing the marginal zone at the border between red pulp and white pulp. The sinuses in (4) are filled with red blood cells (red). (5) venous sinusoids. (-->) indicate dendritic cells (antigen-presenting cells or APC) showing a light nucleus and a distinct nucleolus. (7) macrophage-sheathed capillary.