cell recognition and the immune system

• what is a pathogen 


  microorganisms that cause disease
• examples of pathogens are:

  • bacteria
  • fungi
  • protists
• what is phagocytosis 


  the process in which phagocytes engulf foreign cells or pathogens
• examples of specific/ adaptive immune response:

  • B lymphocytes
  • T lymphocytes
  • memory cells
• example of non specific/ innate immune response:

  • neutrophils
  • macrophages
  • natural killer cells
• what are phagocytes?


  white blood cells that engulf and destroy pathogens
• what organelle helps the phagocytic cells have that help with digestion?

  lysosomes
• what is an antigen?

  a molecule that triggers an immune response against a substance
• what are antibodies

  antibodies are produced by the immune system in response to foreign substances
• out of phagocytes and lymphocytes which are specific responses

  lymphocytes because they produce anti-toxins and antibodies
• the commonest type of white blood cell:

  neutrophils
• structure of neutrophils:

  • lobed nucleus
  • flexible mobile - can squeeze through capillary wall
  • phagocytic - can engulf pathogens
  • many lysosomes
• Clonal Selection

  
  
• what is clonal selection

  when the body produced T and B cells that respond to specific antigens