Acute Inflammation Flashcards
What is inflammation and why is it important?
A response of living tissue to injury
It delivers defensive materials to the site of injury, clears damaged tissues and initiates repair
What is acute inflammation?
The rapid response to an injury to tissue that aims to deliver mediators of host defences
What kinds of things cause acute inflammation?
Foreign bodies Infections Immune reactions Trauma Tissue necrosis
What are the three essential components that make up acute inflammation?
Vascular and cellular reactions
Chemical mediators
Protective functions
What vascular reactions occur in tissue during acute inflammation?
Changes in blood flow: vasoconstriction (secs), vasodilation, increased blood flow, increased permeability, increase in haematocrit, stasis
Exudation of fluid into tissues: increased hydrostatic pressure, loss of protein, increased oncotic pressure, fluid moves out of vessels and causes oedema
What is the difference between exudate and transudate?
Exudate is protein rich and is formed as a result of inflammation
Transudate is protein poor and occurs in normal vessels when the hydrostatic pressure is increase in the capillary (e.g. in heart failure)
What cellular reactions occur in tissues during acute inflammation?
Neutrophils and other inflammatory cells migrate to the site of inflammation
How do neutrophils migrate to sites of inflammation?
Summoned by chemotaxis, activated to higher metabolic state then:
Margination - stick to endothelial surface
Rolling - roll along the endothelial surface
Adhesion - bind to adhesion molecules and stop rolling
Emigration (Diapedesis) - dig themselves out of venules by digesting the cell BM
What chemical mediators of acute inflammation are there and what do they do?
Histamine - increases vascular permeability
Leukotrines - increase vascular permeability
Bradykinin - dilation of blood vessels
Cytokines/chemokines- chemoattraction
Clotting cascades- generate inflammatory mediators
Complement components- C3a, C5a, opsonin C3b
What protective components of acute inflammation are there and what do they do?
Delivery of plasma proteins- dilution of toxins and increased lymphatic drainage to clear the site of inflammation
Infiltration of cells- remove debris
Pain and loss of function- reenforce rest and reduce further damage (bradykinin)
Give some local complications of acute inflammation
Swelling- blockage Exudate- compression Loss of fluid e.g.burns- dehydration Pain Loss of function
Give some systemic complications of acute inflammation
Fever Leukocytosis APP - CRP, fibrinogen Decreased appetite Increased pulse Shock- circulatory failure (bad)
What are the sequelae for acute inflammation, best outcome to worst?
- Complete resolution
- Continued acute inflammation with chronic inflammation (abscess)
- Chronic inflammation and fibrous repair, probably with tissue regeneration
- Death
Give examples of 4 types of exudate that can be seen in inflammation
- Pus/abscess
- Haemorrhagic exudate - destructive infection/malignancy
- Serous exudate - blisters
- Fibrinous exudate
