non-specific

• name the physical and chemical defences 


  skin

  mucous membranes

  stomach acid

  gut flora
• non-specific 


  inflammation

  phagocytosis

  antimicrobial proteins
• lysozyme 


  tears contain lysozyme that kill bacteria by breaking down cell wall

  also found in saliva and nasal secretions
• inflammation 


  Damaged white blood cells and mast cells release histamine

  histamine cause arterioles to dilate

  this increases blood flow to capillaries at infected site

  capillaries become more permeable

  blood plasma leaks out and enters area around infected tissue

  infecting microbes attacked by white blood cells
• stages of phagocytosis 


  are attracted to pathogens due to chemicals released

  pathogen is engulfed

  enclosed in vacuole

  lysosomes fuse with vacuole releasing enzymes that destroy the pathogen
• 2 types of phagocytes 


  neutrophil

  macrophage
• antimicrobial proteins (interferon)


  provides non-specific defence against viruses

  stops viral protein synthesis by binding to ribosome or viral mRNA stopping tRNA from binding to it