Inflammation Flashcards
Acute
minutes to a few days
Main causes of acute inflammation
Allergic reaction/ hypersensitivity.
Infections
Physical injury
Chemical injury
What happens in the vascular phase of acute inflammation ?
Small vessels dilate, Vascular endothelium cells contract thus making spaces between them
What happens in the exudative phase of inflammation ?
Fluid and protein leaking through capillary walls and cells through venules.
Exudate meaning
Leaky/dilated blood vessels so protein and cells in fluid.
Transudate meaning
Passive outflow of fluid when balance of osmotic and hydrostatic pressure change.
Transudate vs Exudate
Transudate has low protein content, few cells.
Exudate has high protein content, may contain some white & red blood cells.
Chemokines and IL-1
Stimulate adhesion molecules on endothelium and white cells
Tumour necrosis factor
Stimulates vascular permeability
Macrophages role
Have the role of clearing debris and dead cells
What is the role of neutrophils during inflammation ?
Migration into tissues
Recognise bacteria by
- formylmethionine at end of surface protein chains
-coating of antibody or complement (C3b)
Phagocytosis is carried out.
Kill bacteria via lysozyme destroying cell wall and via hydrogen peroxide production
Apoptosis
What is the lifespan of neutrophils ?
8-12 hours (short lifespan)
How are basophils/mast cells activated ?
By tissue damage
Or antigens interacting with surface IgE
What do mast cells produce ?
Histamine
Leukotrienes
Prostaglandins
Histamines role
Vascular dilation and permeability
Leukotrienes role
Act as a chemoattractant for other white blood cells
Prostaglandins function
Vascular dilation and pain
What does the coagulation pathway result in ?
Fibrin production to contain infection in a ‘mesh’.
When coagulation factor 12 is activated, bradykinin is produced - vasodilation and sensitises pain receptors.
Abscess
Pus enclosed by fibrin and connective tissue