specific and non-specific immune response 

• non specific (innate) immunity
  • barriers
  • repressive actions
  • blood clotting and wound repair
  • fevers
  • phagocytosis
• neutrophils - lobed nucleus. Phagocytosis
• lymphocytes - formed in the bone marrow and stored in the lymph
• monocytes - macrophages - large kidney shaped nucleus. Phagocytosis
• eosinophils - allergic response
• basophils - mast cells - histamines
• why is fever a useful adaptation:
  • cause it stops the pathogens from replicating
  • increases the body temperature
  • normal core body temperature is 37 degrees
  • this is controlled by the hypothalamus in the brain
  • during infection the large presents of white blood cells causes the hypothalamus to reset,increasing temperature
  • this is because pathogens cannot reproduce as quickly at temperature above 37 degrees,and the specific immune system can work faster
• inflammatory response:
  • inflammation is swelling of skin immediately around the rupture
  • this is characterised by pain,heat and redness
  • mast cells are activated when skin is ruptured they release histamine and cytokines
  • histamine these make blood vessels dilate,causing localised heat and redness.high temperature prevent pathogen reproduction
  • histamines also increase the permeability of the cell wall,causing more tissue fluid to escape causing swelling and the pain
  • cytokines attract WBC to deal with any pathogens

specific immune response

• phagocytes and lysosomes are involved in destroying macrophages
  • phagocytes engulf pathogens/macrophages
  • enclosed in a vacuole
  • lysosomes have enzymes that digests molecules
• antibody actions
  • opsonisation
  • disable pathogen (antibody-antigen complex)
  • agglutination
  • deactivate antitoxins
• how antibodies work
  • antibody - antigen complex acts similar to the opsonin chemical,by stimulating the digested by phagocytosis
  • most pathogens cannot affect the bodies cells once they formed an antibody-antigen complex
  • agglutination - one antibody binds to two pathogens,causing them to clump together
  • this makes pathogens more easily engulfed by phagocytosis
  • neutralisation - antibodies can act as antitoxins binding with toxins produced by pathogens
  • this makes them harmless
• what are lymphocytes
  • lymphocytes are a type of WBC found in the blood and lymph nodes and a transition microscope should be used to see them
  • lymphocytes recognise antigen molecules on the surface of pathogens,and co-ordinate the immune response against that pathogen
  • collectively, lymphocytes can recognise millions
  • two main types of lymphocytes are B and T
  • b-lymphocytes mature in the bone marrow
  • t-lymphocytes mature in the thymus
  • t-helper cells - these cells produce interleukins, a type of cytokine.this stimulate B cell and antibody production,and attracts other t-cells and antibodies.
  • t-killer cells - these cells kill pathogens by producing a chemical called perforin, which makes holes in pathogens cell plasma membranes
  • t-memory cells - these act as the immunological memory,as they remain in the blood for long periods of time.when a second infection occurs,they divide rapidly to form many killer T cells.
  • t-regulator cells - these prevent an autoimmune response by repressing the immune system after the pathogens have been destroyed.
• b-lymphocytes
  • plasma cells - these produce specific antibodies to an invading antigen.these only live for a few days but produce up to 2000 antibodies per second when active
  • b-effector cells - these divide to form plasma cell clones
  • b-memory cells - these remain in the blood for long periods of time,providing immunological memory.if infection occurs these reproduce rapidly and produce the same specific antigen.