Spleen (SEM) | Lymphoid System

Spleen

Scanning electron micrograph (SEM) of red pulp of the spleen. A labyrinth of splenic cords (cords of Billroth) separated by sinusoidal capillaries.

Splenic Cords (cords of Billroth) - cellular aggregations of red/white blood cells and reticular cells/fibers

(yellow) - form the framework of the cords
- Reticular Cells - stellate-shaped cells that wrap around bundles of reticular fibers
- Reticular Fibers - type III collagen that forms cross links
(green) - mostly neutrophils and lymphocytes
(blue) - surface covered with many small projections (pseudopodia)
(red) – unique capillaries that simply terminate and blood flows into the surrounding red pulp
- Sheath of macrophages surround the vessel