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Flashcards in Chronic inflammation Deck (13)
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1
Q

Overview

A

Inflammation, repair and continued tissue destruction occur simultaneously
Lasts weeks, months or years

2
Q

Causes of chronic inflammation

A

Result of previous acute inflammation which failed to
resolve:
• foreign body, grit, retained sutures
• Non-vital tooth causing continued chronic inflammation
at the root apex
• Poor healing due to inadequate blood supply

3
Q

Chronic and low grade from outset

A

Usually in response to chronic low grade stimuli
• Certain micro-organisms such as mycobacteria
responsible for tuberculosis
• Prolonged exposure to toxins e.g. silica responsible for
silicosis; atherosclerosis- response to lipids in plasma
• Autoimmune disease- body mounts an inflammatory
reaction against a component of ‘self. e.g. rheumatoid
arthritis

4
Q

Features of chronic inflammation

A

Minimal vascular changes
Infiltration by chronic inflammatory cells-macrophages,
lymphocytes and plasma cells
Repair- vascular granulation tissue (fibroblasts +
endothelial cells)- may mature to give scarring
Continued tissue destruction- inflammatory agent or
inflammatory cells

5
Q

Macrophages

A

Derived from blood monocyte –> IFN-γ T cells –> activated macrophage
Phagocytosis
Antigen presentation - stimulate immune response
Growth factors
-stimulation of fibroblasts & endothelial cells to promote healing
Cytokines and chemokines attract inflammatory cells and regulate inflammatory response

6
Q

Lymphocytes

A

T cells (cell mediated immunity) move from blood to tissues in response to cytokines (produced by macrophages)
Macrophages and T cells activate each other
T cell immune regulation –> cytotoxic T cell killing // activate humoral immunity (B cells) –> plasma cells and antibodies

7
Q

Eosinophils

A
Resemble neutrophils but
have eosinophilic
cytoplasm.
Important in parasitic
infections
Asthma, type I sensitivity reactions
8
Q

Tissue destruction

A

Products of activated macrophages suchs as free oxygen, proteases
Necrotic tissue promotes further inflammation
Release of enzymes by neutrophils
Cytotoxic T cells
Products of micro-organisms

9
Q

Repair: two mechanisms

A
  1. Regeneration
    - complete resolution to normal tissue
  2. CT deposition and scar formation
    - occurs in tissues not capable of complete regeneration or where there has been prolonged, severe damage
10
Q

Granulation tissue

A

Fibroblasts
Endothelial cells
Stimulated by growth factors from macrophages

11
Q

Granulomatous inflammation e.g. in TB

A

Distinct pattern of chronic inflammation - formation of ‘granulomas’ (giant cells)
-epitheliod macrophages
-multinucleate giant cells
-lymphocytes
Certain micro-orgainsms e.g. mycobacterium which causes TB, syphilis, leprosy
Certain immune reactions e.g. Crohn’s disease; sarcoid
Response to foreign material e.g. sutures

12
Q

Multinucleate giant cells

A

Form by fusion of macrophages

  • foreign body type (non-caseating?)
  • Langhans type (nuclei form neatly round edge) - caseating?
13
Q

TB

A

Cell mediated immune response Th1 and mycobacterium–> activates macrophages –> Continued Th1 response (hyersensitivity) to organisms –> granuloma