Inflammation and Healing

Question 1

What is acute inflammation?

Answer 1

Initial and transient series of tissues reactions to injury

Question 2

5 causes of acute inflammation

Answer 2

Trauma, heat, cold, UV, radiation, microbial infections, chemicals, tissue necrosis, hypersensitivity reactions

Question 3

4 outcomes of acute inflammation

Answer 3

Resolution, progression, suppuration, organisation

Question 4

3 processes involved in acute inflammation

Answer 4

Changes in vessel calibre, increased vascular permeability and formation of fluid exudate, formation of cellular exudate - emigration of neutrophil polymorphs into extravascular space

Question 5

4 physical characteristics of acute inflammation

Answer 5

Rubor, calor, tomur, dolor (also loss of function)

Question 6

Features of the fluid exudate and what it contains

Answer 6

High protein content - up to 50g/L - immunoglobulins, coagulation factors such as fibrinogen

Question 7

4 steps of neutrophil emigrations

Answer 7

Margination into plasmatic zone, adhesion to endothelial cells, pass between endothelial cells, pass through basal lamina and migrate into adventitia

Question 8

6 chemical mediators released by cells

Answer 8

Histamine, lysosomal compounds, prostaglandins, leukotreines, serotonin, chemokines

Question 9

What effects does histamine have in acute inflammation?

Answer 9

Causes vascular dilatation and the immediate transient phase of increased vascular permeability

Question 10

Where is histamine stored?

Answer 10

Stored as preformed granules mainly in mast cells but also in basophil and eosinophil leucocytes and platelets

Question 11

Name the 4 enzymatic cascade systems present in plasma

Answer 11

Coagulation factors, kinin system, complement and the fibrinolytic system

Question 12

4 advantages of these systems

Answer 12

Each step results in amplification of the response, it is safer to have inactive precursors than active mediators, more regulators can modulate response, each step results in end products with possible different activities

Question 13

3 ways the complement system can be activated

Answer 13

In tissue necrosis enzymes capable of activating it are released, during infection formation of antigen-antibody complexes activate it via the classical pathway, endotoxins of Gram negative bacteria can activate it via the alternative pathway, products of kinin and fibrinolytic pathway

Question 14

2 features of a neutrophil polymorph

Answer 14

Multilobulated nucleus, fine granules

Question 15

Define organisation

Answer 15

Organisation of tissues is their replacement by granulation tissue as part of the repair process

Question 16

4 causes of chronic inflammation

Answer 16

Progression from acute, primary chronic inflammation (crohns/sarcoidosis/autoimmue diseases), transplant rejection, organisms that are resistance to phagocytosis

Question 17

3 characteristic cells of chronic inflammation

Answer 17

Lymphocytes, plasma cells and macrophages

Question 18

5 activities of cytokines

Answer 18

Recruitment of macrophages, production of inflammatory mediators, recruitment of other lymphocytes, destruction of target cells, interferon production

Question 19

What is a granuloma?

Answer 19

An aggregate of epithelioid histiocytes

Question 20

What is an epithelioid histiocyte?

Answer 20

Activated macrophage with large vesicular nucleus and eosinophilic cytoplasm

Question 21

When do histiocytic giant cells form?

Answer 21

When particulate matter which is indigestible by macrophages accumulates (silica or bacteria such as tubercle bacilli)

Question 22

3 types of histiocytic giant cells and one characteristic or each

Answer 22

Langhans giant cells - horseshoe arranged nuclei, Foreign body giant cells - randomly scattered nuclei, Touton giant cells - central ring of nuclei/clear peripheral cytoplasm due to accumulated lipid

Question 23

What are the 3 populations of cells according to their potential for renewal and an example of where you would find each

Answer 23

Labile - good capacity to regenerate, eg surface epithelium
Stable - divide at slow rate normally but retain ability to divide when necessary, eg hepatocytes
Permanent - no effective regeneration, eg nerve cells

Question 24

3 mechanisms of pain associated with acute inflammation

Answer 24

Distortion of tissues due to oedema, pus under pressure in an abscess cavity, chemical mediators (bradykinin/prostaglandins/serotonin)

Question 25

2 beneficial effects of inflammation

Answer 25

Walling off of an abscess cavity (reducing the spread of infection) and the destruction of invading microorganisms

Question 26

5 systemic effects of inflammation

Answer 26

Pyrexia, weight loss, reactive hyperplasia of the reticuloendothelial system, haematological changes, amyloidosis

Question 27

What can be measured in the blood that acts as a marker for systemic granulomatous disease?

Answer 27

ACE - secretory product of epithelioid histiocytes

Question 28

2 features of granulation tissue

Answer 28

loops of capillaries supported by myofibroblasts

Question 29

What is healing by first intention?

Answer 29

Narrow wounds, fibrin links both sides, coagulated blood forms scab, capillaries proliferate, fibroblasts secrete collagen, basal epidermal cells proliferate,

Question 30

What is healing by second intention?

Answer 30

Phagocytosis to remove debris, granulation tissue to fill in defects, organisation, early fibrous scar, scar contraction,