Acute inflammation Flashcards
What is acute inflammation?
Series of protective changes that occur in a living organism, as a response to injury
What are the cardinal signs of inflammation?
Rubor - redness
Calor - heat
Tumor - swelling
Dolor - pain
Loss of function
What are the possible aetiologies for acute inflammation?
Micro-organisms
Mechanical - trauma etc
Chemical
Physical - extreme conditions
Dead tissue - necrosis irritates adjacent tissue
Hypersensitivity
What does the micro-circulation refer to?
Capillary beds + feeding and draining arterioles/venules
Extracellular space + everything in it
Lymphatic channels + drainage
What 2 types of pressure govern how the micro-circulation functions?
Colloid osmotic pressure
Hydrostatic
What is the triple response?
Flush
Flare
Wheal (swells)
Poiseuille’s law gives us that blood flow is proportional to…
Radius to the power of 4
Using the idea of Poiseuille’s law, why does local arteriolar dilation cause redness and heat?
Dilation ∴ widening of blood vessel (vasodilation)
Increased ‘r’ ∴ flow goes up
∴ redness and heat
Describe how appropriate stimulus would cause wheal (swelling).
Chemical mediators released cause permeability of vessel walls to increase
Imbalance of starling forces
Net movement of plasma into extravascular space
Exudation ∴ swelling
What is the name given to the fluid that leaks out from the capillaries?
Exudate
exudation of exudate
Describe the composition of exudate.
Plasma fluid
Rich in protein
Immunoglobulins (antibodies) and fibrinogen
Describe normal laminar flow.
White blood cells (neutrophls) central flowing
Erythrocytes surround the white blood cells ‘lane’
What is the difference between inflammatory flow and normal laminar flow?
Erythrocytes aggregate in the centre of the flow
White blood cells (neutrophils) flow on the outer edges of the vessel, near the endothelium
What is margination?
Neutrophils moving to near the endothelial aspect of the lumen
What is pavementing?
Neutrophils adhering to the endothelium
What is emigration?
After pavementing, neutrophils squeezing themselves between endothelial cells (actively)
Movement into the extravascular space
Acute inflammation, specific or not?
Non-specific
Why is a loss of function of an inflamed area a protective response?
Stops you from using that area, so it is protected from further harm
What role to plasma proteins play in the inflammatory process?
They localise the process
What is suppuration?
Formation of pus
Sum up the benefits of acute inflammation.
Rapid response
Cardinal signs + loss of function = protective
Neutrophils destroy pathogens at site of injury + denature antigen for macrophages
^above processes allow resolution and return to normal (healing)
What is the basic naming system (normally) for describing inflammation?
‘Structure’-itis
What is inflammation in the lungs?
Pneumonia
What is inflammation in the pleural cavity?
Pleurisy
At a site of inflammation, neutrophils will destroy anything with foreign antigens, through release of enzymes/oxidants and through phagocytosis.
What does this process produce, and what is the name given to the production of this?
Pus
Suppuration
What is fibrinogen?
Plasma protein
Polymerises to form fibrin
Coagulating factor that clots the exudate
Why is it beneficial to coagulate exudate, at the site of inflammation?
Localises it - stops it spreading into other tissues
Mediators are released in various stages of the inflammatory process. Highlight the collective effects of the mediators, in the pro-inflammatory process.
Vasodilation Increase permeability Neutrophil adhesion Chemotaxi - attracts stuff Itch and pain - protection
Histamine is released in response to a local injury, and is mediated by IgE.
What is it’s effect?
Vasodilation and increased permeability
What is the effect of serotonin release?
Vasoconstriction
What do prostglandins do?
Promote effects of histamines
Inhibit anti-inflammatory cells
