ch 11

• red blood cells: transport O2 and CO2
• white blood cells: protect against pathogens
• platelets: come to the site of bleeding to stop it by forming scabs
• cellular components of blood start in bone marrow, adult stem cells can become any kind of cell
• antigens: found on the surface of cells or anything that enters your body so your immune system can recognise if it should be there
• type A - RBC type A antigens, plasma with anti-B antibodies
• type B - RBC type B antigens, plasma with anti-A antibodies
• type AB - RBC with both type A and B antigens, plasma with no antibodies
• type O - no antigens but both antibodies
• rH factor - antigen on the surface of RBC. if blood has protein you are rH positive
• agglutination - clumping of red blood cells together due to antigen mixing with corresponding antibodies. it is dangerous because the clumps don't fit through capillaries
• blood volume

  1. plasma (55%) - water, protein, nutrients, hormones, salts
  2. cellular components (45%) - red blood cells, white blood cells, platelets
• steps in blood clotting

  1. injury platelets rupture
  2. thromboplastin + Ca2+ make prothrombin
  3. immediately turns into thrombin
  4. thrombin cuts fibrinogen
  5. final product is fibrin
• pathogens: living organisms or non-living viruses that cause infection among body tissue
• bacteria


  -single celled

  -no nucleus
• viruses 


  -non-living

  • reproduce by taking over living cells
• fungi 


  -single or thread like filiments
• protozoa 


  -single cell

  -have nucleus
• first level of defence

  non-specific: skin, cilia, mucus, urine flow, stomach acid, flora, tears
• second level of defence 


  non-specific and non-adaptive: inflammatory response

  1. bacteria enter
  2. platelets clot wound site
  3. vasodilation of blood vessels allowing more blood, plasma and cells to site
  4. macrophages perform phagocytosis
  5. histamines released