Phagocytosis

Phagocytosis is a type of endocytosis in which a cell engulfs large particles or cells, either to destroy them, to feed on them, or to get information from them. It is a crucial mechanism in the immune system that helps to fight against infection.

Process

The process of phagocytosis begins when the cell recognizes the foreign particle or cell. This is often mediated by the binding of antibody molecules to the particle or by the binding of the particle to receptors on the surface of the phagocytic cell. Once the particle is recognized, the cell membrane of the phagocyte extends and engulfs the particle, forming a phagosome. The phagosome then fuses with a lysosome, forming a phagolysosome. The lysosome contains enzymes and acids that kill and digest the particle. The digested material is then released from the cell.

Role in Immune System

Phagocytosis plays a crucial role in the immune system. It is one of the first lines of defense against invading pathogens. Macrophages and neutrophils are the main types of phagocytic cells in the immune system. They can engulf and destroy a wide range of pathogens, including bacteria, viruses, and fungi. Phagocytosis also plays a role in the adaptive immune response by presenting antigens to T cells.

Disorders

Disorders of phagocytosis can lead to increased susceptibility to infections. These disorders can be caused by defects in the phagocytic cells themselves or by defects in the signals that activate phagocytosis. Examples of such disorders include Chronic Granulomatous Disease and Leukocyte Adhesion Deficiency.

See Also

• Endocytosis
• Macrophage
• Neutrophil
• Immune System
• Antibody
• Receptor
• Lysosome
• T cell
• Chronic Granulomatous Disease
• Leukocyte Adhesion Deficiency

Phagocytosis Resources
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