6. Chronic Inflammation Flashcards Preview

EMS - Mechanisms of Disease > 6. Chronic Inflammation > Flashcards

Flashcards in 6. Chronic Inflammation Deck (17):
1

what is the purpose of inflammation?

1. remove the cause of injury
2. initiate repair
3. prevent necrosis

2

what are the dominant cells in chronic inflammation?

lymphocytes, macrophages and plasma cells
granulation and scar tissue is more abundant

3

does chronic inflammation have a primary or secondary onset?

usually primary, but can be sequential from acute inflammation

4

what are the factors precipitating chronic inflammation?

1. infection - TB, leprosy, viruses
2. endogenous materials - uric acid crystals
3. exogenous materials - asbestos, sutures, implants
4. autoimmune - RA, SLE
5. primary granulomatous diseases - crohn's, sarcoidosis

5

when does chronic inflammation have a secondary onset?

most common in suppurative acute inflammation
if the abscess is deep enough, the walls thicken, cause granulation and fibrous tissue.
recurrent acute inflammations also lead to chronic

6

what are the morphological features of chronic inflammation?

infiltration with mononuclear cells
tissue destruction
healing by fibrosis

7

what is a granuloma?

mass of immune cells that forms at sites of infection or inflammation

8

what are the macroscopic features of chronic inflammation?

dependent on the actual disease
chronic abscess cavity
granulomatous in some cases
fibrosis

9

what are the microscopic features of chronic inflammation?

1. cellular infiltrate of lymphocytes, plasma cells and macrophages
2. exudation if fluid is not prominent
3. production of new fibrous tissue from granulation tissue

10

what is the function of macrophages?

phagocytosis of bacteria and damaged tissue

11

what are the 3 processes involved in wound healing?

1. angiogenesis
2. deposition of collagen by fibroblasts
3. inflammatory cells

12

what is the aim of wound healing?

to replace injured tissue with fibrous tissue

13

what is fibrosis?

macrophage induced laying down of connective tissue including collagen during repair of damaged tissue

14

what are histiocytic cells?

multinuclear giant cells which develop when 2 or more macrophages try to engulf the same particle
no known function

15

what are the histological contents of a granuloma?

langerhans giant cells + epithelioid histiocytes + caseous necrosis

16

examples of granulomatous diseases

1. bacterial - TB, leprosy
2. parasitic - schistosomiasis
3. fungal - cryptococcus
4. synthetic materials - silicosis
5. unknown - sarcoidosis, crohn's

17

what are the clinical outcomes of chronic inflammation?

1. persistence of infection
2. prolonged exposure to toxic agents
3. autoimmune diseases eg. RA