Acute Inflammation Flashcards Preview

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Flashcards in Acute Inflammation Deck (11):
1

What are the principle causes of acute inflammation?

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

2

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

3

What is the vascular phase of acute inflammation?

Dilation and increased permeability of vessels

4

What is the exudative phase of acute inflammation?

Fluid and cells escape from permeable venules

5

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

6

Describe the capillaries during acute inflammation

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

7

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

8

What are the 4 enzymatic cascade systems of

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

9

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

10

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

11

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