Reticuloendothelial system

Reticuloendothelial system

The Reticuloendothelial system (RES) (/rɪˌtɪkjʊloʊɛndəʊˈθiːliəl/), also known as the mononuclear phagocyte system or macrophage system, is a part of the immune system that consists of the phagocytic cells located in reticular connective tissue. The cells are primarily monocytes and macrophages, and they accumulate in lymph nodes and the spleen. The Kupffer cells of the liver and tissue histiocytes are also part of the RES.

Etymology

The term "reticuloendothelial system" is derived from the Latin reticulum which means "a net", and endothelium, which is the thin layer of cells that lines the interior surface of blood vessels.

Function

The main function of the RES is to remove worn-out red blood cells and to serve as a defense mechanism against disease. It does this by phagocytosis, a process where cells ingest harmful particles, bacteria, and dead or dying cells.

Related Terms

Phagocytosis: The process by which a cell engulfs a solid particle to form an internal compartment known as a phagosome.
Monocytes: A type of leukocyte, or white blood cell.
Macrophages: A type of white blood cell that engulfs and digests cellular debris, foreign substances, microbes, and cancer cells.
Kupffer Cells: Specialized macrophages located in the liver, lining the walls of the sinusoids.
Histiocytes: Tissue macrophages.
Spleen: An organ that is part of the lymphatic system, which produces lymphocytes, filters the blood, stores blood cells, and destroys old blood cells.
Lymph Nodes: Small, bean-shaped structures that produce and store cells that fight infection and disease.