Flashcards in Chronic Inflammation Deck (19)
List the cell types involved in chronic inflammation.
List the major causes of chronic inflammation.
Arising from acute inflammation
– Large volume of damage
– Inability to remove debris
– Fails to resolve
Arising as a primary lesion
– No preceding acute phase
– Only see chronic changes
Describe the effects of chronic inflammation.
• Granulation tissue is characteristic of organisation
• Results in healing and repair
• Leads to fibrosis and formation of a scar
List factors involved in promoting healing and repair.
• Apposition of edges (no haematoma)- abrasion of edges to remove debris
• Sound nutrition
• Metabolic stability and normality
• Normal inflammatory and coagulation mechanisms
Define the role of angiogenesis in healing and repair.
Promotes wound healing, though must remain checked
List the factors that impair healing and repair.
• Dirty, gaping wound, large haematoma
• Poorly nourished, lack of vitamins C, A
• Abnormal CHO metabolism, diabetes, corticosteroid therapy
• Inhibition of angiogenesis
What are some triggers of primary chronic inflammation
Autoimmune disease - Autoantibodies directed against own cell and tissue components – autoantigens which damage or destroy organs, tissues, cells, cell components e.g. Thyroiditis, rheumatoid disease, pernicious anaemia (chief/parietal cells), systemic lupus erythematosis (nuclear antigen), autoimmune thyroiditis
Lymphocytes, plasma cells, macrophages, fibrosis
Material resistant to digestion e.g. Mycobacteria, Brucella, viruses with cell wall resistant to enzymes
– Sutures, metal and plastic e.g. joint replacements, mineral crystals, glass, which do not provoke immune response
Endogenous substances - Necrotic tissue, keratin, hair which cannot easily be phagocytosed
What are some tissue components of chronic inflammation?
What are granulomas?
• Aggregates of epithelioid macrophages in tissue
• May contain giant cells
• May surround dead material
• May be surrounded by lymphocytes
• Contain neutrophils, eosinophils
• Response to indigestible antigen
• Many are type IV hypersensitivity reactions
Describe giant cells
• Granulomas comprise epithelioid histioytes (macrophages)
• ? fusion of macrophages to form larger cells
• Large cytoplasm; multiple nuclei
Name 4 different types of giant cell
Langhans type - rim of nuclei on the periphery of the cell
Foreign body type - pigmented, random nuclei, pus
Silicone associated - vacuoles contain leaked silicone
Warthin-Finkeldy type - central cluster of nuclei
When are longhand type cells common?
When are warthin-finkeldy giant cells usually seen?
Name some infectious granulomatous diseases and what causes them
• Tuberculosis – Mycobacterium tuberculosis
• Leprosy – Mycobacterium leprae
• Syphilis – Treponema pallidum
What drug combination is used to treat leprosy?
• Dapsone, rifampicin and clofazimine
Give some examples of non-infective granulomas
• Rheumatoid disease - tissue specific auto-immune disease,
• Sarcoidosis – granulomas in skin and lungs etc
• Crohn’s disease – chronic inflammatory bowel disease
Briefly describe the process of wound healing
• Phase of acute inflammation
• Granulation tissue formation
• Local angiogenesis – new vessels grow
• Fibrosis and scar formation
What is a callus?
Callus - an unorganized network of woven bone formed around the ends of a broken bone; it is absorbed as repair is completed (provisional callus), and ultimately replaced by true bone (definitive callus).