Phagocytosis

• Phagocytes are a type of white blood cell but can be of two types: macrophages or neutrophils
• Damaged tissue releases a chemical called histamine, which causes blood vessels to dilate and helps speed up arrival of phagocytes to the site
• Chemical products called cytokines of the pathogens act as attractants causing the phagocyte to move towards the pathogen
• Lysosomes fuse with the phagosome releasing hydrolytic enzymes that digest the contents of the phagosome
• The process of engulfing and destroying foreign material is known as phagocytosis
• Phagocytes attach themselves to the surface of the pathogen and engulf it.
• Phagocyte engulfs pathogen to form a vesicle called a phagosome. Plasma membrane of phagosome is derived from cell surface membrane of phagocyte
• Lysosome contain hydrolytic enzymes which hydrolyse molecules that make up the pathogen
• Soluble products absorbed into cytoplasm of phagocyte. Antigens of pathogen "presented" on cell membrane of phagocyte
• Inflammation occurs at site of infection due to histamine