Acute Inflammation Flashcards
Define acute inflammation
The fundamental response maintaing integrity of the organism.
What is acute inflammation.
Series of protective changes occuring in living tissue as a response to injury.
List some cardinal signs of inflammation.
rubor - redness, darkening
calor - heat
tumor - swelling
dolor - pain
loss of function
Rubor?
Redness or darkening.
Calor?
Heat
Tumour?
Swelling
Dolor?
Pain
Name some causes of acute infammation.
-Microorganisms
-Mechanical/trauma/injury to tissue (all injuries, even sterile ones like surgery).
-Chemcial- upsets stable environment (acid, alkali, bile, urine)
-Physical- extreme conditions
Dead tissues cell necrosis irritates adjacent tissue
-Hypersensitivity
Name the microorganiss which cause acute inflammation.
(bacteria, fungi, viruses, parasites)
Describe some extreme conditions which may cause acute inflammation.
heat=suburn,
cold= forstbite,
ionising radiation
Describe the process of acute inflammation.
-Series of microscopic events localised to affected tissue
-Results in the clinical symptoms and signs of acute inflammation - the cardinal signs
wHAT ARE CAPILLARY BEDS OF THE MICROCIRCULATION FED BY?
Arterioles
What are the cappilary beds of the mircocirculation drained by?
Venules
What is in the extracellular compartment of the microcirculation?
Fluid and molecules
How quicly does the microcirculation respond to stimuli?
Very quickly
What is microcirculation?
Circulation of the blood in the smallest blood vessels
Describe the process of increased flow.
-changes in vessel radius - flow
-change in the permeability of the vessel wall - exudation
-movement of neutrophils from the vessel to the extravascular space
-increased arteriolar radius causes increased local tissue blood flow
-results in observed redness and heat
Describe the process of Increased permeability
-Localised vascular response
-Microvascular bed
-Endothelial leak - fluid and protein not held in vessel lumen (imbalance of Starling forces)
-Locally produced chemical mediators
What is ecudate?
A fluid which is rich in protein and contains mostly plasma. Cotains immunogloblin and fibrinogen.
What is the effect of increased permeability?
-Net movement of plasma from capillaries to extravascular space
-Exudation
What is leaked in exudation?
Ecudate
What are the effects of exudation?
-Oedema formed
-Swelling causes pain - reduce function
What is an oedema?
Oedema is accumulation of fluid in the extravascular space- this explains swelling of tissue in acute inflammation
What does stasis produce?
Change in flow characteristics in the vessel
What is the most important cell in inflammation?
Neutrophil polymorphonuclear leukocyte
->call them either neutrophils, polymorphs or NPLs
What happens f you lose normal laminar flo?
Red blood cells are aggravated in the centre of the lumen and neutrophils get pushed out to the endothelium
Naame the phases of the emigration of neutrophils.
Margination
Pavementing
Emigration
Describe Margination
Neutrophils move endothelial saspect of the lumen.
Describe Pavementing
Neutrophils adhere to endothelium
Define diapedesis
The passive movement of red blood cells through the intact walls of the capillaries, typically accompanying inflammation
Describe Emigration
Neutrophils squeeze between endothelial cells - active process - to extravascular tissues
What is the ideal outcome (resolution) of accute inflammation?
- inciting agent isolated & destroyed
- macrophages move in from blood and phagocytose debris; then leave
- epithelial surfaces regenerate
- inflammatory exudate filters away
- vascular changes return to normal
- inflammation resolves
What are the benefits of acute inflmmation?
- rapid response to non-specific insult
- cardinal signs and loss of function
- transient protection of inflamed area
- neutrophils destroy organisms and denature antigen for macrophages
plasma proteins localise process - resolution and return to normal
Name the four outcomes of acute inflammatoion.
- Resoluation
- Suppuration
- Organisation
- Chronic inflammation
Ho inflmaHow is acute inflammation named?
‘Structure’itis
Meninges= menigitis
Appendix= appendicitis
Name some inflammations which do not follow this ule.
lungs = -pneumonia
pleural cavity = -pleurisy
What do neutrophils do and how do they do it?
Mobile phagocytes
They recognise foreign antigens, move towards it and adhere to it.
What do granules conatin?
Oxidants (H2O) and enzymes (e.g. proteases).
What heppens when the neutrophils adhere to anitgens?
They release the granules which pahgocytise and destroyy the foreign antigen.
What is the consequence of neutrophil action?
Neutophils die when granule contents released and produce a “soup” of fluid, bits of cell, organisms, endogenous proteins - pus.
This pus might extend into other tissues, progressing the inflammation