Reticuloendothelial tissue

The reticuloendothelial system (RES) is a network of cells that are found in various organs and tissues of the body. These cells are responsible for protecting the body from infections, toxins and other foreign agents. The RES is composed of several cell types, including macrophages, dendritic cells, monocytes, and others.

Macrophages are large cells that engulf and digest bacteria, viruses and other foreign agents. They also play an important role in the body's immune response to infections.

Dendritic cells are cells that play a key role in activating the immune system. They capture antigens from the environment and transmit them to T cells.

Monocytes are white blood cells that migrate from the blood into tissues to fight infections. They can transform into macrophages after migrating into tissues.

Reticuloendothelial cells are also involved in regulating the levels of hormones and other biologically active substances in the body. They can capture and process hormones and other substances released from other cells.

Thus, the RES plays an important role in protecting the body from infections and other foreign agents, as well as in regulating the levels of hormones and other biologically active substances.