Microscopic nodes and ducts inside lymphatics and on the surface of internal organs are rich in granulocytes and secretory granules

► Microscopic nodes and ducts exist inside lymph vessels and on the surface of organ. ► The nodes and ducts are covered by a layer of epithelium and endothelium. ► The nodes contain immune cells, enriched with granulocytes and histiocytes. ► The nodes also contain chromaffin cells. ► Secretory granules appear to pass along the ducts.