Leukocyte function but also has a special system of cells scattered throughout the body – the reticuloendothelial system.
It is a system of reticular and endothelial cells, as well as their related connective tissue cells (histiocytes), which is at least one organ that performs the function of absorbing and processing a variety of colloidal and suspended solids, fluids circulating in the internal environment. Following phagocytosis based on the phenomenon of surface activity and adsorption.
All the cells of the reticuloendothelial system as well as blood cells – derived mesenchyme. They constitute the reticular frame forming organs (bone marrow, spleen, lymph nodes), endothelium lining the sinuses spleen and bone marrow sinuses, as well as liver Kupffer cells lining the capillaries it. The connective tissue and especially along the capillary walls and into the omentum and peritoneal cavity has a large accumulation of histiocytes.
The absorption capacity of the cells of this system increases the conversion of fixed cells in wandering. Have the greatest absorbency Kupffer cells, then the spleen cells and other cells of the system. It varies in different animals and different ages.
Between the cells of the reticuloendothelial system and bodily fluids are exchanged constantly with various substances. Some substances are absorbed by the cells of the reticuloendothelial system of the blood and lymph, and other continuous emissions of the blood and lymph.
In the cells of the reticuloendothelial system found breakdown products of proteins, fats and carbohydrates. Consequently, this system – the most important organ of the intermediate metabolism.
The cells of the reticuloendothelial system is constantly moving into the blood as monocytes. The cells of the reticulo-endothelial system hemolysin produced, and they are destroyed erythrocytes and hemoglobin, particularly in the cells located in the liver and spleen. Therefore, in this system, cells accumulate large amounts of iron, and between them and the bone marrow, where blood formation takes place, there is a constant cycle of this element necessary for respiratory function. In the cells of the reticuloendothelial system and iron is deposited, to do with food. The leukocytes are destroyed.