Chronic fucking inflammation Flashcards
what is chronic inflammation?
inflammation in which the cell population is especially:
-lymphocytes
-plasma cells
-macrophages
can lead to necrosis/tissue damage and loss of function
what is the end result of granulation tissue?
scarring and fibrosis - loss of normal tissue function
can chronic inflammation arise from ongoing acute inflammation?
yes
what is the clinical presentation of chronic inflammation?
pain often not specific
malaise and weight loss (TB)
loss of function (crohns disease, leprosy)
why would chronic inflammation arise from acute inflammation?
large volume of damage
inability to remove debris
acute inflammation fails to resolve and progresses
can chronic inflammation arise as a primary lesion only?
yes
what is organisation?
an outcome of acute inflammation that results in healing and repair via granulation tissue, leads to fibrosis and scar formation
what is the mechanism and function of granulation tissue?
ingrowth of capillaries into the inflammatory mass
allows access of plasma proteins
macrophages from blood and tissue
fibroblasts lay down collagen to repair damaged tissues
collagen replaces inflammatory exudate
this patches tissue defects and replaces dead or necrotic tissue
what are some products of granulation tissue?
fibrous tissue -scar
why can fibrosis cause a problem?
it can cause loss of function in organs
can progress to chronic inflammation
what is autoimmune disease?
autoantibodies directed against self cells and self tissue components - autoantigens
what are some effects of autoimmune disease?
damage or destroy organs, tissues, cells, cell components
what are some other causes of primary chronic inflammation?
material resistant to digestion exogenous substances (sutures, metal etc, NO IMMUNE RESPONSE) endogenous substances (necrotic tissues, keratin) granulomatous inflammation (common)
what is the main role of the lymphocyte?
immune response and immune memory
what is the main role of the plasma cell?
antibody production
facilitation of immune response
immune memory
they act with macrophages (presents antigen to immune system)
what are some functions of T cells?
production of cytokines
production of interferons
damage and kill (lyse) other cells and destroy antigens
what do cytokines do?
attract and hold macrophages
activate macrophages
permeability
what is the function of NK cells?
destroy antigens and cells via granule proteins
what are the functions of macrophages?
remove debris
antigen presenting cells in the immune system
produced in the bone marrow and present in blood and tissues
what are some different types of macrophage?
monocyte histiocyte activated macrophage epitheloid cell giant cell
what are some characteristics of macrophages?
motile phagocyte long lived take over from neutrophils contain enzyme produce interferons and other chemicals can influence the progression of chronic inflammation
what are some characteristics of fibroblasts?
motile
metabolically active
make and assemble structural proteins such as collagen
what are the outcomes of chronic inflammation?
ongoing tissue damage and destruction insidious loss of function cellular and stromal response (granulation tissue and angiogenesis) scarring and fibrosis granuloma formation
what is granulomatous inflammation?
characterised by presence of granulomas in tissues and organs
what stimulates granulomatous inflammation?
indigestible antigen
what are granulomas?
aggregates of epitheloid macrophages in tissue
may contain giant cells
contain neutrophils and eosinophils
what are granulomas a response to?
indigestible antigen
how is a giant cell formed?
fusion of macrophages
comprised of epitheliod histiocytes (macrophages)
when would you expect to see langhans type giant cells?
TB
what are some different classifications of giant cells?
langhans
foreign body type
warthin-finkeldy type
what are some examples of infectious granulomatous diseases?
TB
leprosy
syphilis
what is caseous necrosis?
dead tissue surrounded by macrophages, giant cells, lymphocytes
what are some examples of non infective granulomas?
rheumatoid disease
sarcoidosis
crohns disease
what are the phases of clinical wound healing?
phase of acute inflammation
granulation tissue formation
local angiogenesis
fibrosis and scar formation
how much granulation tissue would you expect to see in a wound that has been healed by primary intention?
small amount
what is healing by secondary intention?
method used for larger defects
lots of granulation tissue ingrowth
contraction and scarring
what is the sequence of healing by secondary intention?
injury, clot, acute inflammation, fibrin
granulation tissue ingrowth - angiogenesis
phagocytosis of fibrin
myofibroblasts move in and lay down collagen
contraction of scar
re-epithelialisation
what are factors that favour wound healing?
cleanliness apposition of edges (no haematoma) good nutrition stable, normal metabolism normal inflammatory and coagulation mechanisms
what are factors that impair wound healing?
dirty, gaping wound, large haematoma
poor nutrition
abnormal metabolism, corticosteroid therapy
inhibition of angiogenesis
what does granulation tissue in fracture healing contain along with fibroblasts?
osteoblasts
how is a callus formed?
osteoblasts lay down woven bone
nodules of cartilage present
bone remodelling follows
what are the steps in bone remodelling?
osteoclasts remove dead bone
progressive replacement of woven bone by lamellar bone
reformation of cortical and trabecular bone
what is angiogenesis?
formation of new vessels
what are the steps in angiogenesis?
capillary buds form
vascular endothelial growth factor released by hypoxic cells stimulates proliferation
enzyme secretion aids process
what does angiogenesis enable the blood supply to do in relation to damaged tissue?
allows the blood supply to enter it
how does angiogenesis present in the case of thrombosis?
limits thrombus propagation and re-instates flow.
