acute chronic inflammation

Question 1

what is injured tissue replaced by

Answer 1

dividing parenchymal cells

fibroblastic/glial scar tissue

Question 2

what is acute inflammation mediated by? what happens in acute inflammation?

Answer 2

innate immune system;
rapid onset with rapid resolution
transient vasoconstriction of arterioles-> vasodilation and increased blood flow-> slowing of circulation due to increased permeability of vasculature-> stasis of blood-> exudation of fluid and plasma proteins, possibly pus
redness/swelling/heat/pain

Question 3

what happens in acute serous inflammation

Answer 3

accumulation of fluid in skin (after friction blister or burn)

Question 4

how are cell adhesion molecules expressed on endothelial cells? what is the effect of this

Answer 4

in response to histamine/thrombosis factors-> webel palade bodies release cell-adhesion molecules (P selectin)-> expression on endothelial surface
P&E selectin interact with carbohydrate receptors-> margination-> neutrophils leave central column of blood and roll along endothelium

Question 5

what causes chemotaxis of neutrophils to occur

Answer 5

bacterial products (eg LPS)/components of complement system(especially 5a)/products of lipoxygenase pathway of arachnidonic acid metabolism (eg leukotriene b4)
chemokines eg IL8 are released by endothelial/epithelial/smooth muscle cells

Question 6

how does diapedesis and extravasation occur? what do they mean?

Answer 6

diapedesis is movement ACROSS endothelium
extravasation is movement of cells into tissues following chemokine gradient
P and E-selectin + carb receptors
ICAM-1 + integrin molecules(on wbc)

Question 7

how does chronic inflammation begin

Answer 7

follow acute inflammation
low grade smouldering process (persistent infections/autoimmune diseases/prolonged exposure to non-degradable substances)

Question 8

chronic inflammation characteristics

Answer 8

long duration
associated with macrophages and lymphocytes and plasma cells
proliferation of bv and connective tissue
not sterotypic unlike acute inflammation

Question 9

what happens in chronic granulomatous inflammation

Answer 9

early granuloma (spherical structure; macrophage surrounded by lymphocyte)-> non-caseating epitheloid granuloma (spherical structure surrounded by fibroblast)
OR 
caseating epitheloid granuloma (spherical structure surrounded by fibroblast, has necrosis)