immune system

• non-specific defence systems 

  • The skin
  • The nose
  • The trachea and bronchi
  • The stomach
• types of white blood cell 


  phagocytes

  lymphocytes
• phagocytes 


  engulf foreign cells and digest them (phagocytosis)

  The phagocytes membrane surrounds the pathogen and enzymes found inside the cell break down the pathogen in order to destroy it.
• lymphocytes 


  detect that these are foreign not naturally occurring within your body and produce antibodies. This can take a few days, during which time you may feel ill. The antibodies cause pathogens to stick together and make it easier for phagocytes to engulf them.

  
  

  Some pathogens produce (e.g bacteria) toxins which make you feel ill. Lymphocytes can also produce antitoxins to neutralise these toxins. Both the antibodies and antitoxins are highly specific to the antigen on the pathogen, thus the lymphocytes that produce them are called 'specific'.