External Non-Specific Defence

• why does BV dilate in inflammatory response?

  deliver more blood to area than normal

  increase WBC to help neutralise pathogens

  Increase temp of inflamed; inhibit pathogen acticity
• Why does inflamed area become swollen red and warm?

  Swollen: Histamine (detected tissue damage) dilates BV to increase blood flow to area

  Red: Increase in BC; Increase RBC

  Warm: Blood came from core body (warmer than peripheral)
• why is sweat hostile environment?

  salts

  • fatty acids: kill any pathogen
• what is significance of sebum?

  sebum secretions from oil glands contain substances that kill micro-organism
• mucus?

  secreted by mucus membrane

  • inhibit pathogen entry
• hair?

  traps particles
• acids?

  stomach, vagina, sweat

  • kill pathogen
• lysozyme?

  AB enzyme kill bacteria

  • tear, saliva, sweat, vagina
• cerumen?

  prevent pathogen enter ear

  • acid, lysozymes
• flush?

  body fluids wash a tract

  • prevent colonisation by micro-organism
• barrier?

  hostile environment for pathogen

  • normal bacteria inhabits it
  • sebum secretions from oil glands that contain substances that kill micro-organisms
  • sweat (salt and fatty acids) -> skin uninhabitable