Phagocytosis

• Phagocytosis is carried out by both neutrophils and macrophages.
• Cells under attack produce histamine.
• Pathogens release chemicals.
• These both attract phagocytes (chemotaxis).
• Pathogens may be covered in marker antibodies (from B lymphocytes).
• This stimulates phagocytes to attack as they have receptor proteins which recognise antibody molecules and attach to them.
• Phagocyte membrane engulfs pathogen and traps it in a vacuole (endocytosis).
• Digestive enzymes within lysosomes fuse with phagocytic vacuole and the pathogen is destroyed.
• Undigested remains are removed by exocytosis.