Inflammation III

Question 1

What are the pathological effects of inflammation?

Answer 1

• Increased endothelial permeability
• Increased expression of adhesion molecules
• Chemokine production
• Fever

Question 2

What is suppurative inflammation?

Answer 2

• Acute inflammatory exudate rich in neutrophils
• Common in bacterial infections
• Mixture of neutrophils, necrotic tissue and tissue fluid in exudate

Question 3

Describe serous inflammation

Answer 3

• Accumulation of fluid with low plasma protein and cell content e.g pleural inflammation

Question 4

Describe fibrinous inflammation

Answer 4

• Pattern of acute inflammation - exudate has high plasma protein content
• Deposition of fibrin in tissues
• Forms mat-like sheet on membrane-lined cavities e.g peritoneum

Question 5

Describe necrotising inflammation.

Answer 5

• Virulent organism produces severe tissue damage and extensive cell death
• EXAMPLE: GANGRENE - possible forms of maintenance: amputation and blood vessel construction

Question 6

Describe chronic inflammation

Answer 6

• CAUSES: Persistent injury and inflammatory response is insufficient to completely degrade pathogen

Question 7

What are the causes of chronic inflammation?

Answer 7

• Bout of acute inflammation
• Autoimmune diseases and persistent infections
• Response to malignant tumours and infections

Question 8

What is the role of macrophages in chronic inflammation?

Answer 8

• Antigen presentation to T and B cells
• Release chemotactic factors for other leukocytes
• Stimulates endothelium for adhesion molecule activation
• Phagocytosis

Question 9

What are the roles of eosinophils and basophils?

Answer 9

• EOSINOPHILS - parasitic infections and IgE-mediated allergic reactions
• BASOPHILS - contain mediators such as mast cells. IgE mediated reactions and histamine release

Question 10

Describe the process of chronic inflammation.

Answer 10

• Macrophage and lymphocyte activation
• Growth factors cause fibroblast and endothelial cell proliferation
• Cytokines cause increased collagen synthesis
• Decreased metalloprotease activity = Decreased collagen degradation
• RESULT: FIBROSIS

Question 11

Describe granulomatous inflammation.

Answer 11

• Type of chronic inflammation - presence of granuloma
• GRANULOMA - accumulation of activated macrophages surrounded by rim of lymphocytes
• Macrophages are larger than normal. Have pink cytoplasm. Called ‘epithelioid macrophages’

Question 12

What is the outcome of chronic inflammation?

Answer 12

• Attempt to heal by fibrosis
• Damaged tissues unable to regenerate and replaced by fibrous tissue

Question 13

What is tissue repair and what are its stages?

Answer 13

• Regeneration of damaged tissue by cells of same type
• HEMOSTASIS, INFLAMMATION, REGENERATION, FIBROSIS AND REMODELING

Question 14

Describe the inflammatory phase. PART 1

Answer 14

• Initiated by microbial invasion and tissue damage. Recognition of PAMPs by PRRs
• Inflammasomes release cytokines

Question 15

Describe the inflammatory phase. PART 2

Answer 15

• Damaged blood vessels initiates coagulation
• Mediators attract neutrophils and other inflammatory cells - secrete cytokines, interferons, growth factors

Question 16

Describe the inflammatory phase. PART 3

Answer 16

• Neutrophil polymorphs and tissue macrophages undergo apoptosis
• Type 1 collagen replaces type 3 collagen. Cross linking stabilises wound and causes wound remodelling
• ‘Restoration’ macrophages restore inflammatory cell types to normal levels

Question 17

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Describe the proliferative phase.

Answer 17

• Endothelial proliferation from existing vessels generates and secretes collagen
• Fibroblasts mature and form collagen
• Reduces size of injured site