Acute Inflammation 1

Question 0

Triple response

Answer 0

1. Reddening = vasodilation
2. Flare (red halo) = hyperaemia
3. Wheal (swelling)= oedema

Question 1

Vascular Response: Key Processes

Answer 1

1.Transient vasoconstriction
–neurogenic – occurs within seconds
2.Arteriolar dilation
–axon reflex arc  capillary beds open: red & hot
–histamine, nitric oxide
3.Increased blood viscosity
–blood stasis
–impedes outflow
4.Increased vascular permeability
–fluid enters interstitial space (transudate)
–hallmark feature of AI

Question 2

Increased vascular permeability: transudate vs exudate

Answer 2

Transudate: low protein ( albumin) less than 30g/L, low cells ( less than 1500 cells per micro/L) NON- INFLAMMATORY RESPONSE

Exudate: high protein ( greater than 30g/L), high cells ( greater than 5000 per micro/L) INFLAMMATORY EFFUSION

Question 3

Oedema

Answer 3

Increase in interstitial fluid

Usually classifies as a transudate ( NON- INFLAMMATORY)

Question 4

Increased Vascular Permeability

Answer 4

1. Gaps between endothelial cells
   •Vasoactive mediators (histamine, leukotrienes)
   •VEGF-induced channels
2. Direct endothelial injury
   •Toxins, burns, chemicals
3. Leukocyte-mediated injury to endothelium
   •Leukocyte products (ROS, enzymes)
4. Angiogenesis
   •Leakage from new vessels
5. Radiation damage
   •Sunburn, x-rays, UV radiation damage to endothelial cells

Question 5

Inducers of Acute Inflammation

Answer 5

• Infections
• Trauma (+/- sterile)
• Physical and chemical agents
• Foreign bodies
• Tissue necrosis (“bad death”)
• Hypersensitivity reaction

Question 6

Components of Acute Inflammation

Answer 6

•Vascular Response
–Changes to blood flow and vessel permeability

•Cellular Response
–Recruitment of leukocytes

•Soluble mediators
–Co-ordinators of the tissue response

•Molecular “sensors”
–Control the type of inflammation

Question 7

Acute Inflammation

Answer 7

•Immediate response to tissue damage
•Primarily an innate response
–Cells and molecules of the innate immune system: non-specific
•Local response to limit tissue damage
•Characterised by:
–Leakage of blood proteins (fibrinogen > fibrin)
–Recruitment of leukocytes from the blood
•Inflammatory exudate
–hallmark feature of AI

Question 8

Cardinal Signs of Acute inflammation

Answer 8

1. Heat (calor)
2. Pain (dolor)
3. Redness (rubor)
4. Swelling (tumor)
5. Loss of function (functio laesa)

Question 9

Leukocyte activation

People sometimes say money counts

Answer 9

Production of arachidonic acid metabolites
Secretion/ degranulation of lysosomal enzymes
Secretion of cytokines
Modulation of leukocyte
Cell division induction

Question 10

What are the three types of soluble mediators

Answer 10

Vasoactive amines
Cytokines
Arachidonic acid metabolites

Question 11

What is the arachidonic acid metabolites pathway

Answer 11

Phospholipase forms 5-lipoxygenase and cyclooxygenase

5-lipoxygenase forms 12-lipoxygenase

Question 12

What are cytokines

Answer 12

Activate leukocyte
IL-1, IL-2, TNF-a
Induce acute phase response

Question 13

Tissue necrotic factor are produced by what type of cells?

Answer 13

Macrophages

Question 14

What are interleukins?

Answer 14

Produced by leukocytes
Act of leukocytes
Activate T-cells and neutrophils ( phagocytic cells)

Question 15

What are chemokines?

Answer 15

Activators and chemoattractants for leukocytes

Question 16

Two branches of CHEMOTAXIS

Answer 16

Exogenous- bacterial

Endogenous- chemokines, cytokines

Question 17

Process of phagocytosis

Answer 17

1. Recognition and attachment
2. Engulfment- forming a phagosome
3. Killing and degradation- lysosomes secrete into phagosome
   Oxygen dependent and oxygen independent

Question 18

What do mast cells and basophils produce when they degranulation?

Answer 18

Heparin: prevents thrombosis
Histamine: increases vascular permeability
Leukotrienes: increases vascular permeability

Question 19

Difference between mast cells and basophils

Answer 19

Basophils are short lives, mast cells are long lives

Question 20

What do eosinophils produce when they degranulate?

Answer 20

Enzymes
Toxic proteins
Cytokines
Chemokines
Leukotrienes

Question 21

Leukocytes extravasation

Answer 21

1. Extravasation
Leukocytes move from blood to injury
2. Margination
Leukocytes adhere to endothelial wall
3. Transmigration
Leukocytes move through endothelium
4. Migration 
Leukocytes move into interstitial fluid

Question 22

Types of plasma proteins in exudates

Answer 22

Albumin: Ca, Cu, Zn
Interferrin: Fe
Heptoglobin: haemoglobin
Ceruloplasmin: Fe mechanism
Immunoglobulins: binding antigens

Question 23

Neutrophils produce

Answer 23

Bacteriocidal and oxygen free radicals

Question 24

What is a modified transudate?

Answer 24

High proteins

Low cells

Question 25

Triple response

Answer 25

Redness- vasodilation
Flare- hyperaemia
Wheal- oedema

Question 26

Increased vascular permeability: mechanisms

Answer 26

1. Gaps between endothelial cells
2. Direct endothelial injury
3. Leukocyte- mediated injury to endothelial wall
4. Angiogenesis- leakage from new vessel
5. Radiation

Question 27

Vascular changes to acute inflammation

Answer 27

Transient vasoconstriction: neurogenic
Arteriolar dilation: histamine and nitric oxide
Increased vascular permeability: fluid enters interstitial fluid
Increased blood viscosity: blood stasis, impedes outflow