Inflammation 1-3 🗸 Flashcards
Five causes of inflammation
infection
trauma
foreign bodies
immune reaction
necrosis
Vascular changes in response to injury
changes in blood flow and blood vessel caliber (vasodilation)
changes mediated by histamine and nitric oxide
results in calor and rubor
calor
heat of infected area
rubor
redness of inflammation
5 responses to injury
stasis
margination
rolling
adhesions
transendothelial migration
stasis
blood flow slows as a result of vasodilation
margination
slowed blood vessels allow WBCs to accumulate near the blood vessel wall (neutrophils are the main cell of acute inflammation)
rolling
selectins stimulate WBCs to roll along the cell wall
Adhesions
endothelial expression of cell adhesion molecules (ICAM and VCAM)
Adhesion molecules also expressed on WBCs - integrins and selectins
low affinity initially - affinity increased by proteoglycans + prostaglandins (VCAM and ICAM) and histamine + thrombin (selectins)
transendothelial migration
WBCs able to move through vascular endothelium (leaky)
caused by direct damage or endothelial contraction which is mediated by histamine, bradykinin, substance n and leukotrienes
pass through junctions, diapedesis, transcytosis
chemotaxis
Occurs after WBC has left the blood vessel
cells follow a chemical gradient and move along in
Phagocytosis (inflammation)
recognition and attachment happens first (aided by opsonins)
engulfment, then killing and degradation happens
two reactive species that help kill in phagocytosis and what produces them
oxygen - NADPH oxidase
nitrogen - nitric oxide species
causes of rubor and calor
increase perfusion
slow flow
increased permeability of vessels
tumour (swelling) caused by which vascular changes?
proteins exit the leaky blood vessels causing change in osmotic pressure
dolor (pain)
mediated by prostaglandins and bradykinin
functio laesa
loss of function
What is the outcome of acute inflammation dependant on?
site of injury (capacity for repair)
type of injury (severity, pathogenic organisms)
duration of injury
resolution of inflammation
complete restoration of tissue to normal after the removal of inflammatory components
erosions and abrasions
injury with basement membrane intact
heat rapidly with complete resolution
suppuration
formation of pus - neutrophils, bacteria, inflammatory debris
Empyema
space filled by pus and walled off
organisation in response to inflammation
scarring
What gives increased chances of organisation
lots of necrosis
lots of fibrin
poor blood supply
damage goes beyond the basement membrane