Acute Inflammation Flashcards
What 6 things cause Acute Inflammation?
- Micro-organisms
- Mechanial trauma to tissue
- Chemical changes
- Extreme physical conditions
- Dead tissue
- Hypersensitivity
What are the cardinal signs of inflammation?
- Rubor (redness)
- Calor (heat)
- Loss of function
- Tumor (swelling)
- Dolor (pain)
Aetiology of acute inflammation?
- pathogenic organisms
- trauma
- chemical (acid/alkali or misplaced bile/urine)
- physical conditions (sunburn, frostbite, radiation)
- Dead Tissue irritates adjacent tissue
- Hypersensitivity
Whats microcirculation?
- Capillary beds fed by arterioles & drained by venules.
- Extracellular space & fluids/molecules in it.
- lymphatic channels & drainage
Pathogenesis of acute inflammation:
- changes in vessel radius (flow)
- Changes in vessel wall permeability (exudation)
- neutrophil movement from vessel to extracellular space
Whats the triple response?
Flush. Flare, Wheal.
What are the 3 types of vessel radius change?
1) Transient arteriolar constriction
2) local arteriolar dilation
3) Smooth muscle relaxation
Why increase local blood flow?
To cause rubor & calor
What causes vessel permeability change during acute inflammation?
Local chemical mediators (chemokines) produce a leak in the endothelium
What are the effects of increased vessel permeability?
Think exudation
net movement of plasma fluid & protein from capillaries to extracellular space. (exudation) Includes immunoglobulin & fibrinogen
What is the effect of exudation?
Oedema
Accumulation of fluid in extravascular space.
exaplins swelling, pain & reduced function.
How does increased permeability effect flow?
It slows it down because of increased viscosity. Stasis.
In short what are the 3 stages of neutrophil movement from the vessel to the extravascular space
Margination
Pavementing
Emigration
What is margination?
Nuetrophils move to the endothelial aspect of lumen.
Normal in centre of vessel.
What is pavementing?
Neutrophils adhere to endothelia
What is Emigration?
Neutrophils squeeze between endothelia to outside tissue
What type of neutrophil is most important in inflammation?
Neutrophil Polymorphonuclear leukocyte
What are the steps of the ideal outcome of acute inflammation?
- Inciting agent isolated & destroyed
- macrophages come from blood & phagocytose debris.
- epithelial surfaces regenerate
- exudate filters off
- vessels return to normal
Benefits of acute inflammation?
- Rapid resposne to a non-specific insult
- Cardinal sings protects inflamed area
- neutrophils destroy organisms & denature antigen for macrophages
- localised by plasma proteins
Results of systemic infection?
Septicaemia
Bacteraemia
Toxaemia
Possible outcomes of acute inflammation?
- Resolution (ideal)
- Suppuration (Pus forming)
- Organisation
- Chronic inflammation
