Acute Inflammation 1 Flashcards
What are the cardinal signs of acute inflammation?
- Rubor (redness)
- Calot (heat)
- Tumor (swelling)
- Dolor (pain)
- Loss of function
What are 6 causes of acute inflammation?
- Microorganisms
- Mechanical (trauma)
- Chemical (pH)
- Extreme physical condition (sunburn, frostbite)
- Dead tissue
- Hypersensitivity
What is microcirculation?
- Circulation of blood in capillaries (from arterioles to venules)
- Lymphatic capillaries and ducts
Outline pathogenesis in acute inflammation
- Vessel radius change
- Change in permeability of vessel wall - Exudation
What is exudation?
Movement of neutrophils from vessel to extravascular space
What are the 3 types of vessel radius change?
- Ateriolar constriction
- Ateriolar dilation
- Relaxation of smooth muscle
What is the triple reponse?
Flush, flare, wheal
Why increase radius of blood vessel?
Increases local tissue blood flow
-Redness and heat
What causes changes in vessel wall during acute inflammation?
Locally produced chemical mediators cause an endothelial leak - fluid and protein diffuse to tissue
What are the effect of increased permeability?
Net movement of plasma from capillaries to extravascular space (exudation)
What are the components of exudate?
Fluid which is rich in plasma protein; immunoglobulin and fibrinogen
What are the effects of exudation?
Oedema formed causing tissue to swell and thus causing pain and reducing function
What is oedema?
Accumulation of fluid in extravascular space
Effect of increased permeability on flow
Slows down due to increased viscosity - stasis
In short, what are the stages in the movement of neutrophils into extravascular space?
- Margination
- Pavementing
- Emigration
What occurs in margination?
Neutrophils move to endothelial aspect of lumen
-Normally in centre of vessel
What occurs in pavementing?
Neutrophils adhere to endothelium
What occurs in emigration?
Neutrophils squeeze between endothelial cells (active so requires energy) to extravascular tissues
What is diapedesis?
Passive movement of RBC through leaky capillaries
Describe ideal resolution of acute inflammation?
- Inciting agent destroyed and phagocytosis of debris
- Epithelial surface regenerates
- Exudate filtered away
- Vessel radius normal
- Inflam. resolves
Benefits of acute inflammation
- Rapid and nonspecific
- Cardinal signs protect inflamed area
- Neutrophils destroy and macrophages phagocytose
- Plasma proteins localise process
- Resolution
What are the outcomes of acute inflammation?
- Resolution
- Suppuration
- Organisation
- Chronic inflammation
What is suppuration?
Pus formation
What is organisation?
When tissue unable to regenerate cells, granulation tissue forms scar
