Reticuloendothelial system

The reticuloendothelial system (RES), part of the immune system, consists of the phagocytic cells located in reticular connective tissue, primarily monocytes and macrophages. These cells accumulate in lymph nodes and the spleen. The Kupffer cells of the liver and tissue histiocytes are also part of the RES.

Mononuclear phagocytic system and lymphoreticular system are synonymous with ''RES.