Inflammation Flashcards
Inflammation
Biology reaction to noxious stimulus (such as microbes), burns and trauma
Inflamatio
To set on fire
Five cardinal signs of inflammation
Redness (rubor), swelling (tumor), heat (calor), pain (dolor) and loss of function (functio laesa)
Acute inflammation
Rapid immune response to deliver leucocytes and antibodies to fight infection or injury
What are the three major components of acute inflammation?
Vascular dilation to increase Bloodflow, microvasculature structural changes to allow leucocytes to leave circulation and enter the tissue, emigration, accumulation and activation of leucocytes
Pro inflammatory mediators in vascular smooth-muscle
Histamine, bradykinin and nitric oxide
Mechanisms of increased vascular permeability
Endothelial cells contract, injured endothelial cells detach, increase transport of plasma proteins and fluid from blood vessels into the tissue tissue
Cellular components of acute inflammation
Leucocytes that attach to adhesion molecules at site – act as phagocytes or release granules (neutrophils). Monocytes. Inflammatory mediators
chemotaxis
cells attracted by chemotactic agents
examples of chemoattractants
exogenous - bacterial toxins
endogenous - complement components, cytokines and lipoxygenase pathway products
toll-like receptor
recognise biological pathogens to allow phagocytosis
methods of leucocyte recognition
receptors/GPCRs for microbial products, opsonins, cytokines
how do phagocytes kill engulfed pathogens?
fuse with lysosome where they are degranulated by ROS and enzymes
what are the four morphological patterns of acute inflammation?
fibrinous, purulent, serous and ulcerative
outcomes of acute inflammation
complete resolution, healing by connective tissue replacement with scar tissues (fibrosis), progression into chronic inflammation
Chronic inflammation
Not characterised by the 5 signs of acute
inflammation. Prolonged duration
Causes of chronic
inflammation
Persistent infection by a pathogenic insult, Immune-mediated inflammatory diseases
(autoimmune, allergic), Prolonged exposure to potentially toxic agents
Morphology of chronic
inflammation
Infiltration of mononuclear cells, Tissue destruction, Attempts at healing by connective tissue
replacement
primary cellular infiltration in acute vs chronic inflammation
acute - neutrophils
chronic - macrophages, lymphocytes, plasma cells
Changes in chronic
inflammation
difficult to remove, more lymphocytes and macrophages, less neutrophils, antigen presentation, granulomas, angiogenesis, fibrosis
granuloma
special type of chronic inflammation
caseating
result of mycobacterial infection e.g. TB
non-caseating
autoimmune
Granuloma caused by…
resistance to phagocytosis
sarcoidosis
enlarged lymph nodes
systemic signs associated with chronic inflammation
low grade
fever (+1-4 degrees), weight loss, anaemia
purpose of fever
to denature bacteria proteins, stimulated by cytokines and mediators
Acute phase protein
produced by the liver - C-creative protein (CRP), Fibrinogen, Serum amyloid A (SAA
