1. 1 Antigens combine with antibodies to form antigen- antibody complexes Antigen Antibody Antigen-antibody complex

2. Phagocytes remove most of the complexes, but some lodge in the walls of blood vessels 1 2 Antigens combine with antibodies to form antigen- antibody complexes Antigen Antibody Antigen-antibody complex

3. Phagocytes remove most of the complexes, but some lodge in the walls of blood vessels There the complexes activate complement 1 2 3 Antigens combine with antibodies to form antigen- antibody complexes Antigen Inactive complement Antibody Antigen-antibody complex Active complement

4. Phagocytes remove most of the complexes, but some lodge in the walls of blood vessels There the complexes activate complement 1 2 3 4 Antigen-antibody complexes and activated complement attract and activate neutrophils which release inflammatory chemicals Antigens combine with antibodies to form antigen- antibody complexes Antigen Inactive complement Neutrophil Antibody Antigen-antibody complex Active complement Inflammatory chemicals

5. Phagocytes remove most of the complexes, but some lodge in the walls of blood vessels There the complexes activate complement 1 2 3 4 Antigen-antibody complexes and activated complement attract and activate neutrophils which release inflammatory chemicals Antigens combine with antibodies to form antigen- antibody complexes Antigen Inactive complement 5 Inflammatory chemicals damage underlying blood vessel wall Neutrophil Antibody Antigen-antibody complex Active complement Inflammatory chemicals