Antigens

• How the body's defence system works


  1. Antigens detected by white cells

  2. Phagocytes attack, lymphocytes develop antibody

  3. Lymphocytes form memory cells

  4. Antibodies work against pathogen

  5. Memory cells provide rapid response to future infection
• Antigens


  Molecules on cell surface that white blood cells can detect as 'foreign'
• Antibodies


  Chemicals produced by lymphocytes in response to foreign antigens
• Antibodies can either destroy microorganisms or stick them together for phagocytes to ingest
• During the time it takes for lymphocytes to develop the right antibody, the numbers of pathogens will grow, possibly causing disease symptoms
• The formation of memory cells means that if the same pathogen gets into the body again, the response can be more rapid and the pathogen will be eliminated before symptoms occur
• The person will have become immune to that specific disease