<prompt> Equivalent to macrophages are -KeratinocytesHistiocytesMast cellsMicrophages  <response>: Ans. is b i.e., Histiocytes MonocyteMacrophageso Mononuclear phagocytes MP also known as macrophages or histiocytes are distributed throughout virtual all tissues. The macrophage is the dominant cellular player in chronic inflammation. MP arise from monoblast in the marrowy and they are released into the circulation as monocytes. The monocytes then migrate to tissues and become part of the tissue fixed macrophages. Blood macrophages - Monocytes Tissue macrophages - Histiocyteso Tissue macrophages histiocytes in different tissue are mentioned in following table - Lung : Alveolar macrophages or Dust cells Brain ; Microglia Liver : Kupffer cells Bone: Osteoclasts Skin : Langerhans cells Connective tissue : Histiocytes tissue macrophages Placenta : Hoffbauer cells Kidney : Mesangial cells Spleen : Littoral cells Synovium : Type-A lining cells Spleen : Red pulp sinusoidal lining cells 