Inflammation and repair Flashcards
List the causes of inflammation
Infections, microbial toxins
Tissue necrosis
Foreign bodies and endogenous substances (urate crystals)
Hypersensitivity
What components recognise microbes and damaged cells?
Cellular receptors for microbes, such as TLRs
Sensors of cell damage, such as NLRs
Receptors for Fc tails of antibodies
Complement
What is the inflammasome?
Receptors for cell damage (NLRs) activate the inflammasome, which is multiprotein cytosolic complex. The inflammasome recruits IL-1
How does IL-1 induce inflammation?
IL-1 is recruited by the inflammasone, and IL-1 recruits leukocytes
In which inflammatory diseases is the inflammasone implicated?
Gout/uric acid, metabolic syndrome and obesity-associated T2DM/lipids, aterosclerosis/cholesterol crystals, AD/amyloid
What are the key components of inflammation?
Vascular reaction and cellular response
What are the 5 steps of inflammation?
Recognition
Recruitments of leukocytes
Removal of agent
Regulation of inflammation and
Repair
What are the three major components of acute inflammation?
Vasodilation and increased blood flow
Increased microvascular permeability
Leukocytes arrival and activation
Define exudate
Extravascular fluid that has high protein concentration and contains cellular debris. Its presence implies inflammation and increased vessel permeability
Define transudate
Fluid with low protein content, little cellular debris and low specific gravity. It is produced from osmotic or hydrostatic imbalance without increase in vascular permeability
Is oedema transudate or exudate?
Can be either
Describe vasodilation in inflammation
Early manifestation
Caused by histamine
Involves arterioles and then opening of new capillaries
Increases blood flow, heat and erythema
What is the results of vasodilation and increased vessel permeability?
Slow flow, concentration of red cells and increased viscosity of blood.
Small vessels engorge, leading to stasis, vascular congestion and localised erythema
How are leukocytes recruited to inflammation?
With stasis, leukocytes accumulate along the vascular endothelium. Mediators activate endothelial cells to increase expression of adhesion molecules. Leukocytes adhere to endothelium and then migrate through the vessel wall.
How is increased vascular permeability achieved?
Contraction of endothelial cells
Endothelial injury causing necrosis and detachment, enhanced by leukocyte binding
