Chronic inflammation Flashcards
List the cell types involved in chronic inflammation
Lymphocytes
Macrophages
Plasma Cells
Major causes of chronic inflammation?
arising from acute inflammation
arising as a primary lesion (Primary skin lesions are those which develop as a direct result of the disease process.)
arising from acute inflammation
- Large volume of damage
- Inability to remove what caused acute inflammation before
- Fails to resolve
arising as a primary lesion
No acute phase, only see chronic stages
Can be a result of:-
Auto-immunal disorder
material resistant to cellular digestion
Exogenous substances eg. Sutures (stitches, metal/ plastic e.g joint replacements, glass)
Endogenous subtances eg. Keratin, Hair, necrotic (dead) tissue, can’t be easily phagocytosed
What are some effects of chronic inflammation?
scarring and fibrosis (thickening and scarring of connective tissue, build up of scar tissue in an organ or tissue) granuloma formation (cluster of immune cells
What is chronic inflammation?
body’s response to injury or infection
inflammation that features tissue or organ damage, (necrosis) loss of function ie leprosy- damage to cutaneous nerves so lose sensitivity
tends to be long term
Factors involved in promoting healing and repair?
Cleanliness Apposition of edges Sound nutrition Metabolic stability and normality Normal inflammatory and coagulation mechanisms
symptoms/ clinical presentations of chronic inflammation
often no specific ‘sore bit’
malaise (general feeling of illness/discomfort) and weight loss e.g tb- systemic effect
loss of function- autoimmune thyroiditis (functional gland destruction) hypothyroidism (doesn’t produce enough thyroid hormone
Chron’s disease (GI tract ulceration and fibrosis) pain, diarrhoea, gut obstruction
Leprosy (cutaneous nerve destruction) loss of sensation
Granulation tissue mechanism
capillaries grow into inflammatory mass
access of plasma proteins
macrophages from blood and tissue
fibroblasts lay down collagen to repair damaged tissue
- collagen replaces inflammatory exudate
- patches tissue defects, replaces dead or necrotic tissue
contracts and pulls together
the product of granulation tissue is fibrous tissue- a scar e.g small firm blemish on skin
Primary chronic inflammation:- autoimmune disease
autoimmune disease
self antibodies directed against own cell and tissue components- body attacks itself
damage or destroy organs, tissues, cells, cell components
thyroiditis, rheumatoid disease, sytemic lupus etc
examples of material resistant to digestion
mycobacteria (can cause tb)
brucella (bacteria from animals)
viruses
macrophage mechanisms
motile phagocyte move from blood
long lived
contain enzymes e.g lysozomes
effects of chronic inflammation
increase in lymphocytes, plasma cells, macrophages and fibroblasts
tissues or organ damage (necrosis) and loss of function
involves healing and repair- granulation tissue, scarring and fibrosis
role of Angiogenesis in healing and repair
angiogenesis is part of granulation tissue and repair
- it involves the formation of new blood vessels. Vascular endothelial growth factor (VEGF) is released by many hypoxic (tumour) cells, which stimulate proliferation. Enzyme secretion aids process.
Angiogenesis enables blood supply to enter damaged tissue
describe the sequence of events in healing and repair
injury, blood clot, acute inflammation, fibrin (forms the scab)
many growth factors and cytokines involved
granulation tissue growth- angiogenesis
phagocytosis of fibrin
myofibroblasts move in and lay down collagen
contraction of scar
re-epithelialisation- keratinocytes pushed up from layers of epidermis
What is pilonidal abscess?
hair shafts growing down into the skin- around about it you find inflammation etc. Very painful, curable though
Primary intention
when the dermal edges are close together- ie in apposition and produce a linear scar
secondary intention
larger wound - sides not in apposition
lots of granulation tissue in-growth so mass in the middle
a lot of blood clot too
more untidy scar