MOD 4 - Acute Inflammation Flashcards
what are some of the causes of acute inflammation?
Tissue death (ischaemia, trauma, toxins, chemical insults, thermal injury), Infection (especially bacterial - pyogenic)
what are the purpose of acute inflammation
clear away dead tissues, locally protect from infection, allow access of immune system components
what are the cardinal signs of acute inflammation
calor (heat), rubor (redness), dolor (pain), tumor (swelling), function laesa (disturbance of function)
what are the 3 components of the acute inflammatory response?
Vascular reaction - dilation (rubor) changes in flow, exudative reaction - formation of inflammatory exudate (leaking out of blood vessels/organs - tumor), cellular reaction - migration of inflammatory cells out of vessels
what is pyrexia?
temperature - fever
what does vascular reaction component of the acute inflammatory response involve?
microvascular dilation - leading to initial blood flow to increase - but blood flow is decreased after a short while as the permeability of the blood vessels increase ie volume loss to extracellular space
what are the 2 types of permeability?
mediated - by mediator such as histamine, bradykinin, NO, Luekotriene B4, complement components & non-mediated such as direct dmage to endothelium eg toxins, physical agents
what is contained within the acute inflammatory exudate?
protein rich - contain immunoglobulins & fibrinogens (fibrinogen - convert to fibrin which form a mesh around the cause of inflammation which hopefully contain it.
why is acute inflammatory exudate constantly turning over?
to dilute noxious agent, to spread the inflammatory mediators, to spread antibodies & drugs, to transport pathogens to lymph nodes (stimulate immune reaction)
what is the exudate reaction of the acute inflammatory reaction?
formation of inflammatory exudate
what does the cellular reaction of the acute inflammatory reaction involve?
accumulation of neutrophils in extracellular space
what happens in severe cellular reaction of the acute inflammatory reaction?
accumulation of neutrophils, cellular debris and bacteria will form pus ie pyogenic
Will acute inflammatory response in different part of the body be the same
no - eg bronchus contain a purulent acute inflammatory exudate.
where is neutrophils produced?
bone marrow
when will neutrophils increase?
in acute inflammation
what attracts the neutrophils towards the site of inflammation?
direct chemotaxins
what is the lifespan of neutrophils like?
short lifespan (hours in tissue)
what properties do neutrophils have?
phagocytic, microbiocidal
what are the 2 types of process which break down the pathogens by neutrophils
O2 dependent & O2 independent
which enzyme is used by o2 dependent process to break down pathogen
myeloperoxidase - produce free radials eg H2O2, Cl-, O2-, OH-
which enzymes are involved in o2 independent process of breaking down pathogens by neutrophils?
lysozyme, lactoferrin, cationic proteins
what is pavementing
it is the adhesion of the neutrophil polymorphs and lining up of neutrophil polymorphs along the side of endothelium waiting to leak out of the blood vessels
what happens to the neutrophil polymorphs after the pavementing?
the neutrophil polymorphs will then go down the chemotaxic gradients towards the very site of inflammation ie migration
what are some of the mediators of acute inflammation for vascular dilation?
histamine, PGE2/I2, VIP, NO, PAF
