occurs post C3 activation

C5 splits into C5a and C5b

C6/C7 comples with C5b form membrane bound C5b67

C5b67 is acted on by C8 to stabilize membrane insertion

C9 is polymerized by C8 to generate a pore structure

C3a, C4a, and C5a directly trigger mast cell degrantulation

release preformed mediators

release newly synthesized

C3b coats microbial surface which promotes adhesion of foreign antigen to phagocyte (phag has receptors for C3b)

receptor site is CR1

activation of phospholipase C via G protein

release of calcium

assembly of contractile elements within cell (actin & myosin)

locomotion along chemical gradient

IL-1 mediates fever

cytokines released from activated neutrophils and macrophages

cytokines act on hypothalamus causing release of prostaglandins

prostaglandins increase temperature set point

body initiates heat mechanisms, i.e. shivering and vasoconstriction

IL-1, IL-6, and tumor necrosis factor target the liver which is where these proteins are manufactured

reach maximum level in 10 - 40 hours

some are "used up" during process so levels may be lower than normal