Inflammation Flashcards
What is Inflammation?
Tissue response to injury or infection, characterised by increased blood flow and entry of leukocytes into tissue
4 cardinal signs of inflammation
Redness, swelling, heat, pain
4 things used in inflammation?
Mast cells,neutrophils, complements, chemokines
What are complements:
A set of about 20 different proteins acting in an enzymatic amplification cascade system to generate a number of active components
3 ways of activating complement are:
Classical, Lectin, Alternative
Activation of complement leads to 3:
Release of peptides active in inflammation
Deposition of C3b which is a powerful opsonin
Membrane damage and lysis
Classical Activation Path:
Ag binds to IgG or IgM
Alternative pathway activation:
Direct interaction with polysaccharide on microbe surfaces, or PRRs used
Lectin Pathway complement Activation:
Bacterial cell walls have sugars, Mannose Binding Lectin recognises the sugar
What do all 3 paths end in making?
C3 convertase that breaks C3 to C3a and C3b
Lectin and classical C3 convertase name:
C4b2a3b
Alt path C3 convertase:
C3bBb3b
What happens after C3 split?
C5 split to C5 a and C5b
What is the membrane attack complex made of?
c5b-c9
How does the membrane attack complex work?
C8 acts like a dagger, C9 forms a pore allowing solutes in and out
Which complement opsonises?
C3b
Which complements lead to mast cell degranulation?
C3a and C5a
What else does C3b do?
Binds to Ab and Ag, RBC has a receptor for it - carries immune complex to liver and spleen
What does C3d do?
Activates B lymphocytes and the adaptive system
What else does C5a do?
chemotaxis
4 things released from mast cells:
Phospholipase A2, vasoactive amines, cytokines, chemotactic factors
What happens to Phospholipase A2?
changes into arachidonic acid which either changes into prostaglandins or leukotrienes
What does Histmanine do?
Increases Vascular permeability so neutrophils enter site of inflammation
Which complements attract neutrophils?
C5a and C3a
