four signs of inflammation
erythema (redness)
heat
edema
pain
erythema (redness) precipitating event
vasodilation and increased blood flow
heat precipitating event
vasodilation and increased blood flow
edema precipitating event
increased vascular permeability and hydrostatic pressure, causing filtration into interstitial spaces
pain causes
direct trauma
edema causing pressure
nerve endings swelling
chemical mediation
acute inflammation
chiefly edema including fluid and plasma proteins and neutrophilic migration
chronic inflammation
includes lymphocytes, plasma cells, and macrophage infiltration
angiogenesis/neovascularization
fibrosis
tissue destruction
conditions that would cause acute inflammation
infections
tissue necrosis
foreign bodies
immune reactions
conditions that would cause chronic inflammation
extensive necrosis
site where tissue regeneration is not possible: heart, CNS, PNS
underlying cause is not addressed; persistent injurious agent
repeated episodes of acute inflammation
what is granulomatous inflammation
aggregate of macrophages and lymphocytes
what is exudate
high protein fluid with high cellular content that is dependent upon increased vascular permeability
what is transudate
low protein fluid with minimal cellular content that is dependent upon Starling’s forces causing filtration with no increase in vascular permeability
what is effusion
leakage of either exudate or transudate into anatomic or potential space
what is the goal of vascular alterations in inflammation
increase movement of plasma proteins and circulating cells out of intravascular space to get to the site of injury
the role of leukocytes in inflammation
remove/eliminate injurious stimulus
release toxic substances to kill, inactivate, and degrade pathogens
clean up the area by phagocytosis
release growth factors for healing/regeneration
what is process of leukocytes role in inflammation
statis
margination: possible because of adhesion molecules that bind leukocytes to other leukocytes as well as capillaries/venules
diapedesis
chemotaxis
stasis
engorgement of blood vessels causing a slowing of blood flow in the region
margination
accumulation of leukocytes to endothelial cells of blood vessel walls
diapedesis
leukocytes actively migrate out of blood vessel, by squeezing between endothelial cells, to reach the interstitial space
chemotaxis
the use of chemotactic agents (chemokines) which attract other cells to move into the area
what is the role of the lymphatic system in the inflammatory response
> lymphatic vessels drain exudate from the interstitium reducing edema and removing inflammatory stimuli and leukocytes
phagocytes present antigens to immunocompetent B and T cells in the lymph nodes leading to the enlargement of lymph nodes (lymphadenopathy)
what is lymphangitis
inflammation of the lymphatic vessels characterized by red streaks under the skin and painful to palpation
describe histamine
> synthesized and stored in granules within mast cells, basophils, and platelets
causes endothelial contraction leading to increased vascular permeability and exudation, vasodilation, bronchoconstriction
inactivated in <30 minutes
what are the two phospholipid derived inflammatory mediators
platelet activating factor (PAF)
arachidonic acid derivatives
