outcomes of acute inflammation Flashcards
what are systemic manifestations of acute inflammation?
- fever
- malaise (general discomfort & illness)
- loss of appetite
- nausea
- haemotological changes (increased erythrocytes sedimentation rate, leukocytosis)
what are outcomes of inflammation?
- resolution
- suppuration
- scarring or fibrosis
- chronic inflammation
what is resolution outcome?
- everything back to normal
ideal conditions:
= good regenerative capacity
= minimal tissue damage/cell death
= quick elimination
what is suppuration outcome?
= formation of pus - mix of dead & alive neutrophils, debris, bacteria etc
- if walled off = can form abscess (pocket of pus)
what is organisation/fibrosis/scarring outcome?
- 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
what is primary intention of skin healing?
2 edges of wound brought together, fibrin joins edges (weakly) - overtime, epidermal regrowth & collagen synthesis makes stronger join
what is secondary intention of skin healing?
tissue defect filled in by granulation tissue, can’t bring edges together so epithelial regrowth over the surface & fibrous scar forms & contracts over time
describe (simply) bone healing
initial haematoma/inflammatory response →callous formation (not particularly strong but holds together) → replaced eventually by stronger lamellar bone
how does liver heal?
- Loss of hepatocytes without damage to architecture = Can get complete healing
- Loss of hepatocytes plus damage to architecture = Fibrous scarring / nodules
how does kidney heal?
- 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
how does smooth muscle heal?
- vascular smooth muscle cells can regenerate
- Other smooth muscle cells … not so much
- Damaged muscle is replaced by scar tissue (makes less movement)
how does neural tissue heal?
- CNS doesn’t repair well
- peripheral nerves may regrow but recovery is variable
how does acute inflammation progress to chronic inflammation?
- if causative agent NOT removed
- cellular exudate starts to change -> from neutrophils to lymphocytes, plasma cells & macrophages
*chronic inflammation CAN sometimes occur as primary
what is most common type of acute inflammation to progress to chronic?
suppurative - most likely to fail
= collection of pus, abscess formation and walling off with granulation & fibrous tissue
what can favour progression from acute to chronic inflammation?
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
what are macroscopic signs of chronic inflammation?
- chronic ulcer
- chronic abscess cavity
- fibrosis/thickening of tissue
what are the cells of chronic inflammation and what do they look like?
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)
what are cytokines function?
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
what is a granuloma?
=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)
what is involved in granulomatous inflammation and what are associated conditions?
- 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
how do giant cells form?
when macrophages collide when more than 1 tries to eat same particle so end up with huge multi-nucleated cell
what are types of giant cell and what does nuclei look like in each one?
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
