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Flashcards in Acute Inflammation Deck (11):

What are the principle causes of acute inflammation?

1. Microbial infection
2. Hypersensitivity reactions
3. Physical agents
4. Chemical agents


What are physical characteristics of acute inflammation?

+ Red (rubor)
- dilation of blood vessels

+ Hot (calor)
- peripheral increase in temperature
- due to increased blood flow (hyperaemia)

+ Swollen (tumor)
- due mainly to oedema
- some contribution from inflammatory cells

+ Painful/tender (dolor)
- stimulation of nerve endings by pressure and chemical mediators

+ Loss of function


What is the vascular phase of acute inflammation?

Dilation and increased permeability of vessels


What is the exudative phase of acute inflammation?

Fluid and cells escape from permeable venules


What are the features of an exudate?

+ High protein content

+ Proteins include immunoglobulins
- may be important for destruction of invading organisms

+ Fibrinogen > fibrin
- on extravascular contact
- acutely inflamed organ surfaces commonly covered by fibrin

+ High turnover
- continuously removed via lymphatics


Describe the capillaries during acute inflammation

+ Open pre-capillary sphincter
+ Dilation of the arterioles
+ Dilation of the venules
+ Most capillaries full
+ Net flow out


What are features of increased vascular permeability?

+ Produced by chemical mediators including histamine, bradykinin

+ Involves stimulation of endothelial cell cytoskeleton by chemical mediators

+ Confined to post capillary venules

+ Transient, intercellular gaps appear

+ Endothelial cells are not damaged in this way


What are the 4 enzymatic cascade systems of

1. Complement system
2. The Kinin System
3. Coagulation factors
4. Fibrinolytic system


What are the beneficial effects of acute inflammation?

DILUTION OF TOXINS: allows them to be carried away by lymphatics

ENTRY OF ANTIBODIES: due to increased vascular permeability

FIBRIN FORMATION: impedes movement of microorganisms

TRANSPORT OF DRUGS: e.g antibiotics

DELIVERY OF NUTRIENTS AND OXYGEN: aided by increased fluid flow

STIMULATION OF IMMUNE RESPONSE: fluid exudate containing antigens reaches local lymph nodes


What are the harmful effects of acute inflammation?

+ Digestion of normal tissues

+ Swelling e.g laryngeal oedema, brain swelling

+ Inappropriate inflammatory response e.g type I hypersensitivity


What are the systemic effects of acute inflammation?

+ Constitutional symptoms include malaise, anorexia, nausea

+ Weight loss due to negative nitrogen balance, particularly when there is extensive chronic inflammation

+ Reactive hyperplasia of the reticuloendothelial system

+ Haematological changes

+ Increases erythrocyte sedimentation rate
- anaemia
- leucocytosis