L3.15 Chronic Inflammation

Question 1

What are the features of chronic inflammation?

Answer 1

• Ongoing tissue damage at same time as body attempts healing
• Mononuclear cells (macrophages and lymphocytes) and plasma cells depending on the cause of inflammation
• Formation of fibroblasts and scar tissue
• Can last months to years
• Persists until damaging stimulus is eradicated
• Scar tissue formed

Question 2

What is haemosiderin?

Answer 2

Iron storage molecule, stains macrophages brown/gold when they try to digest RBC and have to convert the iron to haemosiderin

Question 3

What are germinal centres?

Answer 3

Normal feature in lymphoid tissues with development of humeral mediated immunity. Normal component of lymphoid tissues. As the B cells are exposed to antigen and become plasma cells they become larger and form a germinal centre - usually paler than surrounding cells.

Question 4

What are the features of granulomatous inflammation?

Answer 4

• epithelial macrophages (elongated nucleus)
• multinucleate giant cell
• necrosis
• sometimes cells converge to form granuloma

Question 5

Why do macrophages present CD4 T cells with an antigen?

Answer 5

To release: interferon gamma (activates macrophages) and IL-2 (activated T lymphocytes for TH1)