4. Acute Inflammation Flashcards
What is inflammation?
Reaction of vascularised living tissue to a local injury
What is the purpose of inflammation?
Eliminate threat and necrotic cells
Begin healing
What are the causes of inflammation?
Infective Chemical Physical Immune Necrotic tissue
What type of cells are associated with acute inflammation?
Neutrophils
What type of cells are associated with chronic inflammation?
Mononuclear
What are the 5 signs of inflammation?
Heat Redness Swelling Pain Loss of function
What causes heat and redness at the site of inflammation?
Vasodilation
What causes swelling at the site of inflammation?
Vascular permeability
What causes pain at the site of inflammation?
Mediator release
What happens as part of the vascular response?
Vasodilation and increased vascular permeability
What fluid is lost as a result of the vascular response?
Exudate (protein-rich)
What happens as a result of the loss of exudate?
Increased concentration of RBCs causes blood stasis
Why is exudate pushed out of blood vessels?
Vasodilation causes increased blood flow and higher hydrostatic pressure
What are the steps in the cellular response?
Margination Rolling Pavementing Transmigration Chemotaxis Oponisation Phagocytosis
What is margination?
Blood stasis causes WBCs to congregate at endothelium
Causes endothelial activation and mediator release
What is rolling?
Neutrophils roll along surface of endothelium
Briefly bind
What is rolling mediated by?
Selectins
What is pavementing?
Neutrophils firmly adhere to endothelial cells
What is pavementing mediated by?
Integrins
ICAM-1
VCAM-1
What is transmigration?
Cells slip between gaps in endothelium
What is transmigration mediated by?
PECAM-1
What is oponisation?
‘cooking’ of bacterium by phagocytes
What is used in the process of oponisation?
Immunoglobulins and C3b
What do vasoactive amines cause?
Vascular dilation
Leaking
Name 2 vasoactive amines
Histamine
Serotonin
What is the classical pathway complement system?
Requires antibodies to activate
What is the alternative pathway of the complement system?
Activated by the microbial surface
What role does the complement system play in immunity?
‘Mac Attack’
Membrane Attack Complex punches a hole in the membrane
What are the effects of the complement system?
Vascular permeability and vasodilation
Chemotaxis
What leads to the formation of Bradykinin?
Kinin cascade
What are the effects of bradykinin?
Increased permeability and dilatation
Pain
What is arachiodonic acid metabolised to?
Leucotrienes and prostaglandins
What prevents prostaglandin production?
Aspirin and NSAIDs
What effects does platelet activating factor have?
Aggregation of platelets
Vaso and broncho constriction
What factors cause vasodilatation?
Vasoactive amines Prostaglandins Bradykinin Complement system NO
What factors cause vascular leakage?
Vasoactive amines tissue damage Complement system Leucotrienes PAF Bradykinin
What factors cause chemotaxis?
Complement system
Leucotrienes
Cytokines
Bacterial products
What factors cause pain?
Prostaglandins
Bradykinin
Oedema
What factors cause tissue damage?
Lysosomal enzymes
Oxygen metabolites
NO
What are the benefits of inflammation?
Dilute and destroy toxins Arrival of antibodies, drugs, nutrients, oxygen Fibrin is produced Remove tissue debris Stimulate the immune response
What is axomal flow?
RBCs travel in centre of blood vessel
What is the plasmatic zone?
Around the walls where plasma usually flows
What is Lewis’ Triple Response?
Flush (red line from capillary dilation)
Flare (arteriolar dilation)
Wheal
What is Catarrhal inflammation?
Acute inflammation and increased mucus secretion
