Macroscopic signs of acute inflammation
1) Redness (rubor)
2) Swelling (tumor)
3) Heat (calor)
4) Pain (dolor)
5) Loss of function
Microscopic signs of acute inflammation
1) Dilation of arterioles
2) Leakage of plasma into tissue
3) Margination and exudation of white cells into tissue
Blood vessels during acute inflammation
1) VERY brief vasoconstriction of arterioles
2) Vasodilation of arterioles (increased blood flow, at slower rate) due to NO, prostaglandin, etc.
3) Increased hydrostatic pressure in capillaries and postcapillary venules
4) Edema (fluid leakage from venules)
5) Leukocyte margination then diapedesis then exudation then finally chemotaxis to infection site
Leukocytes getting from blood to tissues
1) Margination: go to sides of venules
2) Rolling: roll and adhere weakly to endothelium of venules (using selectins)
3) Adhesion: stick strongly to endothelium wall (using integrins)
4) Diapedesis: insert between endothelial cells (by intercellular junctions)
5) Exudation: crawl through walls of venules into extravascular tissue
6) Chemotaxis: hone to site of injury in tissue
The complex physiological process designed to rid the body of damaged/necrotic tissue or foreign invaders.
What is pus?
Neutrophils and cellular/bacterial debris
What happens to people with leukocyte adhesion deficiency (LAD)?
Their neutrophils do not have functional integrins so cannot adhere to the endothelium.
Frequent and severe infections, and inability to combat them
Necrosis but no pus because no neutrophils in the tissue!
Kinetics of Inflammation
Edema (at 0.5 days)
Neutrophil influx (at 1 day)
Monocyte/macrophage (at 2 days)