Chronic Inflammation Flashcards
Define chronic inflmmation.
Chronic inflammation is also referred to asslow, long-term inflammation lasting for prolonged periods of several months to years
Discuss the cell types which are most common regarding chronic inflammation.
Inflammation in which the cell population is especially:
-lymphocytes
-plasma cells
-macrophages
What happens to tissues and organs when there is chronic inflammation
Become necrotic leading to loss of function.
What does chronic inflammation carry on from?
Acute inflammation.
Does there always need to be acute inflammtation for chronic inflammtion to take place?
No.
oten arises itself.
Discuss two areas of healing/repair.
granulation tissue
scarring and fibrosis
When do we see chronic inflammation?
Arising from acute inflammation or arising as a primary lesion
Discuss the clinical presentation of chronic inflammation.
-often no specific “sore bit”
-malaise and weight loss
-loss of function
What is a charecteristic of organization?
Granulation tissue.
Define angiogenesis.
New vessel formation.
What is VEGF?
Vascular Endothelial Growth Factor (VEGF) released by hypoxic cells stimulates proliferation
Whereabouts can we see angiogenesis?
-Angiogenesis and organsiation in thrombus
-Angiogenesis in mlaigant tumours
-Fibrosis and scarring in atheroscelorsis.
Learn more in later lectures so this should be enough?
Describe the mechanism of granulation tissue.
Capillaries grow into inflammatory mass allowing access of plasma proteins.
Macrophages from blood and tissue
fibroblasts lay down collagen to repair damaged tissue and collagen replaces inflammatory exudate.
Describe the function of granulation tissue.
Patches tissue defects.
Relaces dead or necrotic tissue.
Contracts and pulls together.
Helps to restore normal function.
name the products of granulation tissue.
-fibrous tissue - scar e.g small firm blemish on skin
-fibrosis as a problem->adhesions between loops of bowel following peritonitis
-chronic inflammation
name the most common type of chronic inflammation.
Autoimmune disease
What happens in autoimmune disease?
Autoantibodies direceted against own cll and tissue components. Can destroy tissues, organs, cells, cell components.
What can cause primary chronic inflammation?
-Material resistant to digestion (mycobacertia, viruses etc. Cell wall resistant to enzymes).
-Exogeneous substances
-Endogeneous substances
-Granulation Inflammation common
Give examples of exogenous substances.
Sutures, metal and plastic joint replaceens mineral crystals, glass.
Give examples of endogenous substances.
-Necrotic tissue, keratin, hair
These substances cannot easily be phagocytosed
Discuss and describe lymphocytes.
-Cells that are part of immune system
-Small round cells with lots of subtypes and functions
-Main types of lymphocyte=
T-cell
B-cell
-Main functions=
immune response
immune memory
Descibe plasma cells.
Differentiated B-cell
Antibody production
Intermediate size
Describe the mechanisms of B cells.
Differentiate to plasma cells
Facilitate immune responsea
Act with macrophagea
Immune memory
Describe T cell mechanisms.
T-cells produce cytokines
T-cells produce interferons
Damage and kill (lyse) other cells and destroy antigen
What do netural killer cells do?
NK cell destroy antigens and cells
Describe macrophages.
Removes debris
Role in immune system - antigen presenting cell
Found in bone marrow, blood tissues
Discuss the mechanisms of macrophages.
Motile phagocyte move from blood
Long lived
Take over from neutrophils
Contain enzymes eg lysozyme
Produce interferons and other chemicals using destroy, influence process
DISCUSS FIBROBLASTS.
Motile cells
Metabolically active
Make and assemble structural proteins (collagen)
granulomatous inflmmation is charecterised by the prsense of what?
Granulomas in tissues and organs.
What is granulomatous inflammation stimulated by?
Indigestible antigen.
Granulomas…
-Are aggregates of epithelioid macrophages in tissue.
-May contain giant cells
-May surround dead material
-May be surrounded by lymphocytes
-Contain neutrophils, eosinophils
-Respond to indigestible antigen
-Many are type IV hypersensitivity reactions
Name some non-infective gramulas.
Crohn’s disease
Rheumatoid disease
Wound healing is the process of…
Healing damaged tissue
What is the process of surgical healing?
Healing by primary intention.
What is the process of larger defect healiing?
Healing by secondary intention.
Summaris the sequence of events in wound healing.
-Injury, blood clot, acute inflammation, fibrin
-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
WHAT FACTORS WILL FAVOUR WOUND HEALING?
-Cleanliness
Apposition of edges so no haematoma
-Sound nutrition
-Metabolic stability and normality
-Normal inflammatory and coagulation mechanisms
What will impair wound healing?
-Dirty, gaping wooun, large haematoma
-Poorly nourished, lack of vitamins A ad C
-Abnormal CHO metabolism, diabetes, corticosteroid therapy
Describe fractiure healing.
-Same principles as healing at any site
-Modified by situation in bone
-Have to repair bony structure as well as soft tissue
Describe the sequence of events for fracture healing
-Caused by trauma, fracture, haematoma
-Bits of dead bone and soft tissue
-Acute inflammation, organisation, granulation tissue, macrophages remove debris
-Granulation tissue contains osteoblasts as well as fibroblasts
Describe Callus formation.
-Osteoblasts lay down woven bone
-Nodules of cartilage present
-Followed by bone remodelling
Describe bone remodelling.
-Osteoclasts remove dead bone
-Progressive replacement of woven bone by lamellar bone
-Reformation of cortical and trabecular bone
The product of a acture repair is called??
How do macrophages assist with tissue organisation?
Macrophages release proteases, cytokines and growth factors, contributing to tissue organisation.
