Lecture 3 - Acute Inflammation Flashcards
What is Inflammation?
The response of living tissue to injury
What is the aim of acute inflammation?
Limits damage
What does it mean by referring to acute inflammation as stereotyped?
The response is the same regardless of the damage
What is the relative duration of acute inflammation?
Short lived
What are the 2 phases of acute inflammation?
Vascular Phase
Cellular Phase
Generally, what happens in the vascular phase of inflammation?
Change in blood flow and accumulation of exudate
Generally, what happens in the cellular phase of acute inflammation?
Delivery of neutrophils
What can cause inflammation?
Pretty much anything
Trauma
Micro-organisms
Hypersensitivity
What are the 5 clinical signs of acute inflammation?
Rubor
Calor
Tumor
Dolor
Functio laesa
What does Rubor mean?
Redness
What is Calor?
Heat
What is Tumor?
Swelling
What is Dolor?
Pain
What is Functio laesa?
Loss of function
What are the 3 changes that happen in the Vascular phase?
Vasoconstriction
Vasodilatation
Increased permeability
What signs does the vasodilation stage of the vascular phase of acute inflammation cause?
Calor
Rubor
What is Starlings Law?
The movement of fluid through the blood vessel is controlled by the balance of hydrostatic pressure and oncotic pressure
What is hydrostatic pressure?
The pressure exerted on a vessel wall by fluid
What is oncotic pressure?
The pressure exerted by proteins trying to draw fluid back into blood vessels.
What happens in the increased permeability stage of acute inflammation?
Plasma proteins move into interstital space
Increased interstitial oncotic pressure and decreased capillary oncotic pressure
Fluid is drawn out by the interstitial oncotic pressure and capillary hydrostatic pressure into interstitial space
What affect does the fluid being drawn out of the blood vessels have on the blood in acute inflammation?
Increased viscosity
Reduced blood flow through vessel
What is Stasis?
When blood flow is reduced/flows more slowly through vessels since its thicker
What is exudate?
Protein rich fluid
How is exudate produced?
INCREASED VASCULAR PERMEABILITY produces protein rich fluid
Produced in inflammation
What is transudate and when is it produced?
Fluid produced as a result of increased capillary hydrostatic pressure and reduced oncotic pressure
VASCULAR PERMEABILITY DOESNT CHANGE
What conditions produce transudate?
Heart failure
Hepatic failure
Renal failure
How is transudate produced in heart failure?
Blood pools in blood vessels increasing hydrostatic pressure
How is transudate produced in hepatic failure?
Liver responsible for producing plasma proteins
Hepatic failure = decreased oncotic pressure
What are the 3 ways by which blood vessels increase their permeability?
Endothelial cells retract (become smaller)
Direct injury to endothelial cells
Leukocyte Dependant injury to endothelial cells
What stimulates the retraction of endothelial cells?
Histamines
Nitric oxide
How is the vascular phase effective to minimise damage?
Fluid in interstital spaces dilutes toxins
Exudate delivers proteins (fibrin- mesh limits spread of toxin)
Where does the fluid released into the interstitial space drain to?
Lymph nodes
What is the main white blood cell involved in acute inflammation?
Neutrophil
What is a key feature of a neutrophil?
Tri-lobular nucleus
What affect does stasis have on the blood cells in the vessel?
Margination
What is margination?
When the cells migrate to the borders of the blood vessels
What are the 4 steps to neutrophils escaping vessels?
Margination
Rolling
Adhesion
Emigration
What is another word for emigration?
Diapedesis
What are the 2 adhesion molecules important in the migration of neutrophils from blood vessels?
Selectins
Integrins
Which adhesion molecules are responsible for rolling of neutrophils?
Selectins
What is the strength of the bonds formed between the Selectins on the endothelial cells and the neutrophils?
Weak bonds