Acute Inflammation Flashcards
What are the 5 R’s of the immune response
Recognition
Recruitment
Removal
Regulation
Resolution
What does the complement do
Recruits neutrophils and monocytes
How does innate immunity work (generally)
Pattern recognition receptors bind to pathogen and trigger cytokine cascade
What do PRRs recognize
Pathogen associated molecular patterns
Damage associated molecular patterns
What are the main removal mechanisms used by innate immunity
Intracellular killing
Extracellular secretion and effectors
Direct cell-mediated killing
Who does intracellular killing
Neutrophils, monocytes, macrophages, mast cells, dendritic cells
What happens during intracellular killing
-Detection
-Internalization
-Destruction
Who can opsonize bacteria
complement or antibodies
what are the mechanisms for extracellular secretion and effectors
Degranulation
Neutrophil extracellular traps (NETs)
What happens during degranulation
Neutrophils, eosinophils, and mast cells release their granules
Granules release proteolytic enzymes into the intracellular space
How do NETs work
Neutrophils throw out ‘webs’ mostly comprised of their DNA
Bind to pathogens
Form a physical barrier
Who does the direct cell-mediated killing
Natural killer cells
What are the cardinal signs of inflammation
redness
warmth
swelling
pain
loss of function
What are the components of acute inflammation
Dilation of small vessels
Increased vascular permeability
Emigration of neutrophils
What is the hallmark of acute inflammation
Increased vascular permeability
What is early fluid leakage like
low protein, low cellularity
What is early fluid leakage called
transudate
Talk to me about fibrin
Produced when thrombin cleaves fibrinogen
Friable threads and plaques
Yellow or pink/red
Often seen in body cavities
Goes with acute things
What are the steps of the leukocyte adhesion cascade
margination
rolling
firm adhesion
transmigration
What happens during margination
Change in blood flow causes neutrophils to drop out of the laminar flow & come into contact with the epithelium
What happens during rolling
Neutrophils express ligands that bind to selectins and form LOOSE attachments
What happens during firm adhesion
Mediated by integrins
Chemokines at the injury activate leukocytes –> low-affinity integrins –> high-affinity integrins
Neutrophils change shape to be flatter
What happens during transmigration
chemokines and intracellular adhesion molecules stimulate leukocytes to migrate through endothelial spaces - ‘walk’ them through
Describe exudate
Viscous, opaque
Flecks of fibrin
Very cellular
Can remove damage
Dead neutrophils –> pus
What causes redness
Increased blood flow and vascular permeability
What causes warmth
Increased blood flow
What causes swelling
edema, cell accumulation
What causes pain
vet school
tissue damage, inflammatory mediators
What causes loss of function
Pain, tissue damage
