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Pathology & Physiology (Subject) / PIPs (Lesson)
- Def. Phagocytosis "The ingestion and digestion of micro-organisms and damaged/dead tissue by neutrophils and macrophages"
- Mechanism Phagocytosis 1. Binding of pathogen to cellular receptor on the phagocyte 2. Pseudoponia of cytoplasm surround the pathogen 3. Fusion of the pseudoponia, forming a phagocytic vacuole/phagosome 4. Digestion of the pathogen: a) Oxygen-dependent: highly reactive oxygen species and free radicals in the phagolysosome digest the pathogen b) Oxygen-independent: lysosomes filled with pre-formed toxic substances (digestive enzymes) fuse with the phagosome --> phagolysosome