Acute and Chronic Inflammation Flashcards
What are the cardinal signs of inflammation?
rubor (redness)
calor (heat)
tumor (swelling)
dolor (pain)
loss of function
What is erythema?
What could have caused it?
superficial reddening of the skin as a result of inflammation
contact with an irritant chemical, prolonged sun exposure
What is the simplest indicator of acute inflammation?
increase in white blood cell count in the peripheral blood
What are vascular changes in the process of inflammation?
vasodilation - increase blood flow
vascular permeaility
increased adhesion of white blood cells
stasis and concentration of RBC’s
What is the purpose of vascular stasis?
slowing of the blood in the blood stream allows chemical mediators and inflammatory cells to respond to the stimulus
What chemical mediators promote vasodilation?
histamine, prostaglandins and NO
What are PAMP’s?
What do they do?
pathogen-associated molecular patterns
bind to pattern recognition receptors (PRRs) on macrophages which causes the macrophage to release inflammatory mediators
What is diapedesis?
movement of leukocytes out of the circulatory system towards the site of tissue damage or infection
What causes endothelial cells near the site of infection to express cellular adhesion molecules?
release of cytokines by macrophages at the site of inflammation
What is the first step of leukocyte extravasation (diapedesis)?
CAPTURE
selectin ligand (PSGL-1) on leukocyte cell surface binds to P selectin on endothelial cell
What are the five steps of the leukocyte adhesion cascade?
capture
rolling
slow rolling
firm adhesion
transmigration
What happens during ROLLING?
bonds between P-selectin and PSGL-1 are formed at the leading edge and broken at the trailing edge
What must be present for a leukocyte to migrate across resting endothelium?
chemoattractants
What are three causes of chronic inflammation?
persistant infection
prolonged exposure to potentially toxic agents
autoimmunity (rheumatoid arthritis, MS)
What is autoimmunity?
inappropriate inflammatory response when there are no foreign substances to fight off
Describe the cellular events of acute inflammation?
cellular recruitment and activation of neutrophils (polymorphonuclear leukocytes)
What causes rubor and calor?
vasodilation
the increased blood flow causes redness and warmth
What causes tumor?
increased permeability leading to exudation of protein rich fluid into the extravascular space
How do blood vessels alter their permeability?
endothelial cells contract, widening intercellular gaps
How does colloid osmotic pressure change after inflammation?
decreases because after vascular permeability has been altered as a response to acute inflammation a protein rich fluid (exudate) leaks out
What are the possible outcomes of acute inflammation?
progresses to chronic inflammation
normal function
pus formation
healing leading to fibrosis and loss of normal function
What chemical mediators are preformed (within secretory granules)?
histamine - mast cells, basophils and platelets
serotonin - platelets
lysosomal enzymes - neutrophils, macrophages
What are macrophages called in the blood?
monocytes
Where do T lymphocytes mature?
thymus gland
What do integrin receptors on a neutrophil bind to on the endothelium?
immunoglobin superfamily
