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Flashcards in Inflammation Deck (10)
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What is the purpose of inflammation?

A reaction to infection or tissue damage that delivers leukocytes and plasma proteins to the site of injury to prevent further damage


Vascular dilation

One of the earliest signs of acute inflammation

A rapid increase in blood flow results in heat and redness

Induced by histamine, bradykinin and nitric oxide


Cardinal signs of inflammation

redness, heat, pain, swelling, loss of function


Permeability changes

Inflammation causes the microvasculature to become more permeable

This allows plasma proteins and leukocytes to leave the circulation and causes swelling

It is achieved by endothelial cells contracting and detaching and an increase in transport through endothelial cells


Accumulation of leukocytes at injury site

Leukocytes that accumulate at the damaged tissue do so by extravasation/diapedesis

This is achieved by adhesion molecules and chemotaxis



Common chemoattractants include bacterial products, complement components, cytokines and products of the lipooxygenase pathway


Downstream effects of inflammation

-Phagocytosis at the infection side
-Opsonisation of the pathogen
-Destruction of microbes by anti-microbial pathways
-Activation of the kinin, clotting and fibrinolytic pathways


Kinin system

Activated following tissue damage by Hageman factor (XII)

Factor XII activates prekallikrein to form kallikrein

Kallikrein cleaves kininogen to form bradykinin

Bradykinin causes vessel dilation, increased vascular permeability and smooth muscle contraction


Fibrinolytic system

Activated by Hageman factor (XII) which activates a cascade that produces plasmin

Plasmin breaks down fibrin clots, activates enzymes required for collagen remodelling and promotes angiogenesis


Clotting system

Activated by Hageman factor (XII) which leads to a cascade that results in thrombin production

Thrombin leads to clot formation, activates platelets and causes the release of fibrinopeptides