Outcomes of acute inflammation

Question 1

what are systemic manifestations of acute inflammation?

Answer 1

• fever
• malaise (general discomfort & illness)
• loss of appetite
• nausea
• haemotological changes (increased erythrocytes sedimentation rate, leukocytosis)

Question 2

what are outcomes of inflammation?

Answer 2

• resolution
• suppuration
• scarring or fibrosis
• chronic inflammation

Question 3

what is resolution outcome?

Answer 3

• everything back to normal

ideal conditions:
= good regenerative capacity
= minimal tissue damage/cell death
= quick elimination

Question 4

what is suppuration outcome?

Answer 4

= formation of pus - mix of dead & alive neutrophils, debris, bacteria etc

• if walled off = can form abscess (pocket of pus)

Question 5

what is organisation/fibrosis/scarring outcome?

Answer 5

• secondary healing - formation of granulation tissue (scar forming)
• can occur when substantial amounts of tissue loss or large amounts of fibrin
  -new capillaries lead to more macrophages lead to proliferation of fibroblasts -> fibrosis/scarring

Question 6

what is primary intention of skin healing?

Answer 6

2 edges of wound brought together, fibrin joins edges (weakly) - overtime, epidermal regrowth & collagen synthesis makes stronger join

Question 7

what is secondary intention of skin healing?

Answer 7

tissue defect filled in by granulation tissue, can’t bring edges together so epithelial regrowth over the surface & fibrous scar forms & contracts over time

Question 8

describe (simply) bone healing

Answer 8

initial haematoma/inflammatory response →callous formation (not particularly strong but holds together) → replaced eventually by stronger lamellar bone

Question 9

how does liver heal?

Answer 9

• Loss of hepatocytes without damage to architecture = Can get complete healing
• Loss of hepatocytes plus damage to architecture = Fibrous scarring / nodules

Question 10

how does kidney heal?

Answer 10

• Epithelium can regenerate, architecture can’t
• Similar to liver
• Loss of tubular epithelium only can regenerate/repopulate cells
• Destruction of glomerulus or damage to interstitium usually results in scarring / impaired function

Question 11

how does smooth muscle heal?

Answer 11

• vascular smooth muscle cells can regenerate
• Other smooth muscle cells … not so much
• Damaged muscle is replaced by scar tissue (makes less movement)

Question 12

how does neural tissue heal?

Answer 12

• CNS doesn’t repair well
• peripheral nerves may regrow but recovery is variable

Question 13

how does acute inflammation progress to chronic inflammation?

Answer 13

• if causative agent NOT removed
• cellular exudate starts to change -> from neutrophils to lymphocytes, plasma cells & macrophages

*chronic inflammation CAN sometimes occur as primary

Question 14

what is most common type of acute inflammation to progress to chronic?

Answer 14

suppurative - most likely to fail
= collection of pus, abscess formation and walling off with granulation & fibrous tissue

Question 15

what can favour progression from acute to chronic inflammation?

Answer 15

presence of foreign material
- the material cannot be digested/broken down
- often provokes granulomatous inflammation/foreign body giant cells

occurring cycle of acute inflammation then healing

*most acute inflammation resolves

Question 16

what are macroscopic signs of chronic inflammation?

Answer 16

• chronic ulcer
• chronic abscess cavity
• fibrosis/thickening of tissue

Question 17

what are the cells of chronic inflammation and what do they look like?

Answer 17

lymphocytes (small purple dots- circle)
plasma cells (fried egg)
macrophages (bigger blobby ones- like big fried eggs)
eosinophils (tomatoes with sunglasses on - due to bilobed nucleus)

Question 18

what are cytokines function?

Answer 18

small proteins which enhance cell mediated immunity & enhance antibody response

examples
=cell signalling (IL’s, TNF alpha) promoting chemotaxis (chemokines)
= antiviral defences (interferon’s) promote apoptosis

Question 19

what is a granuloma?

Answer 19

=organized collection of immune cells that form in response to persistent stimuli that the body is unable to eliminate

= made of collection of histiocytes (monocytes -macrophages & dendritic cells)

Question 20

what is involved in granulomatous inflammation and what are associated conditions?

Answer 20

• involves formation of giant cells by macrophages colliding
  lots of associated conditions e.g. foreign body reactions, infections (tuberculosis), sarcoidosis= unkown chronic disease (systemic disease), crohns disease

Question 21

how do giant cells form?

Answer 21

when macrophages collide when more than 1 tries to eat same particle so end up with huge multi-nucleated cell

Question 22

what are types of giant cell and what does nuclei look like in each one?

Answer 22

foreign body type - nuclei randomly scattered

langhans - often seen in TB, horseshoe nuclei

touton type - lipid breakdown & xanthomas, neat little circles of nuclei

=they’re all multi-nucleated