Lymphatic Systems The Thymus

Low mag of the thymus Cortex (C) Medulla (M)

High mag of the medulla of the thymus Dark nuclei = T-cells Larger nuclei = endothelial reticular cells Arrow = Hassell’s Corpuscle

Lymphatic Systems Lymph Nodes

Diagram of a lymph node

Cx = cortex w/ lymphatic nodules (F); M = medulla; C = CT capsule Low mag of a lymph node Cx = cortex w/ lymphatic nodules (F); M = medulla; C = CT capsule

A lymphatic nodule with germinal center (GC)

Non-encapsulated Lymphatic Nodules Lymphatic Systems Non-encapsulated Lymphatic Nodules

Peyers Patches = lymphatic nodules in the ileum

Low mag of a palatine or lingual tonsil

Palatine Tonsil w/ SS non-K (arrow) Pharyngeal Tonsil w/ Resp epith (arrow = nodule)

Lymphatic Systems The Spleen

Diagram of the Spleen

Low magnification of the Spleen CT Trabeculae White pulp (lymphatic nodules) Thick CT capsule CT Trabeculae Red Pulp

White pulp Red Pulp Lymphatic nodules CT Trabeculae

Circulatory System in the Spleen

Red Pulp White Pulp White Pulp Red Pulp

High mag of the splenic red pulp

SEM of the endothelial cells of the sinusoids