specific and non-specific immunity

• what is the immune system?

  your body's defence against germs
• white blood cells are the primary defenders of your body, they are produced in the bone marrow
• what are the four types of white blood cells?

  B cells, T cells, Neutrophils, lymphocytes
• what is the function of neutrophils?

  they engulf and destroy bacteria
• what is the function of lymphocytes?

  they recognise and attack foreign invaders
• what is the function of B cells?


  they produce antibodies, proteins that bind to and neutralise foreign substances
• what is the function of T cells?

  directly attack infected and cancer cells
• complement system - a group of proteins that help destroy bacteria and other pathogens
• what is the body's first line of defence against pathogens?

  mucous and skin membranes,, they act as a barrier to keep harmful microorganisms out
• lymph nodes are bean shaped organs that filter lymph fluid, which contains white blood cells and other immune cells
• how does the immune system work?

  recognition, activation, attack, memory
• non specific / innate immunity provides an immediate response, its the first line of defence and acts immediately upon encountering a foreign invader
• non specific / innate immunity doesn't target specific pathogens, but work against a wide range of threats
• non specific / innate immunity - physical barriers:

  • skin
  • mucous membranes
  • cilia
• non specific / innate immunity - chemical barriers:


  • stomach acid
  • tears
  • saliva
• non specific / innate immunity - phagocytic cells:


  • neutrophils
  • microphages
• non specific / innate immunity - natural killer cells:


  • destroy virus infected and tumour cells
• non specific / innate immunity - inflammatory response:


  • redness
  • swelling
  • heat
  • pain
• specific immunity provides a delayed response, it takes time to develop after initial exposure to a pathogen
• specific immunity gives a targeted response, it recognises and attacks specific antigens on the pathogen
• specific immunity can remember past infections and respond more quickly to future encounters with the same pathogen
• what are the components of specific immunity?

  T cells, B cells, antibodies
• antibodies are y shaped proteins that bind to antigens and help to neutralise foreign susbtances