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Flashcards in 7 Chronic inflammation Deck (17)
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1
Q

What is the purpose of inflammation?

A

Remove the cause of injury.
Remove necrosis.
Initiate repair.

2
Q

Contrast acute vs chronic inflammation.

A

Fast onset vs slow.
Prominent vs subtle signs.
Mild and self limiting vs severe and progressive.
Neutrophils based vs macrophage and lymphocyte based.

3
Q

Five sources of primary chronic inflammation.

A
Primary granulomatous diseases.
Exogenous material.
Auto-immune.
Endogenous material.
Infections.
4
Q

Describe 2 ways acute inflammation may become secondary chronic inflammation.

A

Supportive acute inflammation can forms abscess, walls thicken. Granulation and fibrous tissue forms.
OR
Recurrent acute to chronic.

5
Q

What is the macroscopic feature of chronic inflammation?

A

Fibrosis - more prominent when inflammatory infiltrate has stopped.
Dependant on disease.

6
Q

What are the microscopic features of chronic inflammation? (3).

A

Cellular infiltrate of lymphocyte, plasma cells and macrophages.
Exudation fluid is not prominent.
Production of new fibrous tissue from granulation tissue.

7
Q

What do cytokines do in chronic inflammation? (4).

A

Attract macrophages.
Attract neutrophils and histamine - increasing permeability.
Cause perforins to kill cells.
Produce interferons to activate NK cells and macrophages.

8
Q

What is the role of macrophages in chronic inflammation?

A

Increase inflammation.
Release cytokines to signal monocytes which enter tissue via leukocyte extraversion (recruitment).
Proliferate.
Trapped in tissue by inhibiting factor.

9
Q

How do macrophages change the structure of tissue around them in chronic inflammation?

A

Low O2 content makes them produce angiogenesis inducing factors.
Induce cells to re-epitheliase wound and create granulation tissue.

10
Q

What does granulation tissue formation involve and what is its aim?

A

To repair injured tissue by fibrosis.

Angiogenesis. Fibroblasts deposit collagen. Inflammatory cells.

11
Q

What is fibrosis?

Fibroma?

A

Formation of excess fibrous connective tissue during repair (scarring).

Fibroma = arise form 1 cell line.

12
Q

What is a granuloma?

A

Aggregate of epithelioid histiocytes, lymphocytes and histolytic giant cells.

13
Q

What are histolytic giant cells?

How and where do they form?

A

Multinucleate (>100) giant cells. Develop when two macrophage try to engulf one particle. Not phagocytic anymore.

Form where material is indigestible - tubercle bacilli with resistant cell walls.

14
Q

List 4 infectious causes of granulomatous diseases:

1 mineral cause:

A

TB.
Leprosy.
Schistosomiasis.
Cryptococcus.

Silicosis.

15
Q

Describe the stages granuloma in TB. (4)

A
  1. Inhale MTB. Invades alveolar macrophage via mannose receptor. Multiplies. 1wk.
  2. 2-3wks. Proliferation.
  3. Proliferation and phagocytosis are balanced. 90% stay here. Not contagious.
  4. Reactivation 1-2yr later. 5%. Proliferation, cavity formed. Active, symptomatic infection. Contagious. >Immunocompromised.
16
Q

What is a round complex in TB stage 3?

A

Tb and infected macrophages in centre with normal macrophages surrounding it.

17
Q

Describe the layers in a caseous granuloma.

A

Caseous necrosis -> langerhans type cells +epithelioid macrophages -> lymphocytes and plasma cells -> fibroblasts producing collagen.