The reticuloendothelial or mononuclear phagocytic system encompasses a range of cells capable of phagocytosis - macrophages and monocytes. They are either freely circulating within the blood or fixed to various connective tissues. Examples of the site of fixed cells includes pulmonary alveoli, liver sinusoids, skin, spleen and joints.
The RES functions to:
- remove senescent cells from circulation
- provide phagocytic cells for both inflammatory and immune responses