2.2 POJA-L974. Scheme of secondary lymphatic nodule in spleen (human)

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2.2  POJA-L974

Title: Scheme of secondary lymphatic nodule in spleen (human)

Description: (A): Histological impression of a follicle or nodule
(B): Outline of impression

1. pulpa artery 
2. central artery
3. lymphatic sheath
4. lymph nodule
5. thymus-dependent area (periarterial lymphatic sheath or PALS), composed of Th subset lymphocytes
6. mantle zone with mainly naïve B lymphocytes
7. lighter-stained germinal centre with B-memory lymphocytes, reticular cells and macrophages
8. dendritic antigen-presenting cells (APC, border cells, metallophilic cells)
9. anastomosing capillaries within a reticulin scaffold surrounded by dendritic APC
10. marginal sinus zone (perilymphoid zone) between the red and white pulps.

This zone immediately surrounds the nodule and is composed of a reticulin scaffold with APC. The zone comprises concentrically arranged anastomosing fine vascular channels that receive the blood from radial arterioles from the central artery or arteriole. About 10% of the blood is drained into the sinusoids or directly into venous sinuses located on the outer portion of the marginal zone.  In the perilymphoid zone the marginal zone sinusoids are arranged in three concentric systems: marginal zone network followed by marginal sinuses and perimarginal cavernous sinuses enclosing the APC. This zone is thought to be involved in phagocytosis and or antigen-presenting to initiate an immune reaction.
11. Red pulp with sinusoids
12. Rectangle is displayed in the scheme of electron microscopy (see POJA –L976A)

Keywords/Mesh: lymphatic tissue, spleen, white pulp, lymphatic nodule, germinal centre, reticular tissue, marginal zone, mantle zone, dendritic APC, histology, POJA collection