Acute Inflammation

• what is the first line of defence

  physical and chemical barriers
• what is the second line of defence

  inflammation
• what happens to tissue when it is damaged or cells die

  acute inflammation
• Acute inflammation always happens no matter the cause of damage
• what is the role of acute inflammation

  • clear away dead tissue
  • protect against local infection
  • allow immune system to access damaged area
  • facilitate healing
• acute inflammation is the initial response of living tissues to cell damage
• what is the duration of acute inflammation

  short
• what is the duration of chronic inflammation

  long
• Does acute inflammation tend to be painful 


  yes
• Does chronic inflammation tend to be painful

  no
• chronic inflammation is gradual and ongoing
• acute inflammation is suddenly onset
• Characteristics of Acute inflammation

  • short duration
  • sudden onset
  • painful
• Characteristics of chronic inflammation

  • long duration
  • gradual and ongoing
  • not usually painful
• what are the cardinal signs of acute inflammation

  • redness
  • swelling
  • heat
  • pain
  • loss of function
• what is the Latin for the cardinal signs of acute inflammation

  • rubour
  • tumor
  • calor
  • dolor
• rubour 


  redness
• tumor 


  swelling
• calor


  heat
• dolor


  pain
• Acute inflammation response

  • dilation of small blood vessels
  • increases blood flow
  • increases permeability of small blood vessels
• what is margination 


  neutrophils move and adhere to capillary wall
• what is pavementation 


  layer of neutrophils form
• what is emigration 


  marginated neutrophils pass through the capillary walls to damaged tissue
• what are the components of exudate

  • water
  • salts
  • proteins
  • antibodies
  • neutrophils
• what causes small blood vessels to increase in permeability

  chemical mediators
• what causes dilation of small blood vessels

  chemical mediators
• what is the function of water and salts in exudate

  dilute and buffer toxic substances
• what is the function of fibrin in exudate

  forms a network to trap microorganisms
• what is the function of antibodies in exudate

  help destroy microorganisms
• what is the function of neutrophils in exudate

  phagocytosis
• what is the main cell in acute inflammation

  neutrophils
• what is chemotaxis

  directional movement of cells due to attracting chemicals
• what is the role of neutrophils in acute inflammation

  • emigrated neutrophils from blood vessels migrate to inflammation site
  • directional movement of neutrophils due to attracting chemical = chemotaxis
• why is the directional movement of neutrophils important

  otherwise movement of migrated cells would be random
• what is the function of neutrophils

  • break down cells, tissue debris and fibrin
  • kill microorganisms by phagocytosis
  • secrete chemicals for chemotaxis
• Describe the sequence of events in phagocytosis

  1. Neutrophil binds to bacterium by receptor
  2. Pseudopodia form, these encircle the bacterium to engulf it in a phagosome
  3. Lysosome granules fuse with phagosome and discharge enzyme contents
  4. Enzymes kill and digest the bacterium
• what is the lifespan of neutrophils

  3-5 days
• neutrophils die at the site of infection
• what is suppuration 


  formation of pus