Inflammation

Question 1

Inflammation triggers

Answer 1

1) Macrophages recgonise a pathogen and start to release cytokines
2) Complement system triggers degranulation of mast cells, basophils and eiosinophils —> which releases cytokines
3) Mast cells, basophils and eosinophils respond directly to allergens or tissue damage by degranulation - releasing cytokines

— Once triggered inflammation provides a positive feedback loop that activates these triggers further leading to greater inflammation

Question 2

Inflammation localised effects on tissues:

Answer 2

Activation of endothelial cells to display adhesion molecules

Vasodilation

Increased vascular permeability

Question 3

Activation of pro-inflammatory systems:

Answer 3

Clotting system is activated

Kinin system is activated

Complement system is further activated

Question 4

Inflammation causing recruitment and activation of cells in the immune system:

Answer 4

Further macrophages are activated

Monocytes are recruited to the site of inflammation and become macrophages

Mast cells and basophils are activated and release more cytokines

Eosinophils are activated and release more cytokines

Neutrophils are recruited to site of inflammation for phagocytosis

Question 5

Inflammation leading to an acute phase response:

Answer 5

[Neutrophils and macrophages respond to inflammation by releasing even more cytokines]

IL-1 - CNS
IL-6 - Liver (acute phase proteins/ opsonins)
IL-8 - Neutrophils
IL-2/-12 - NK cells
TNF-α - All of the above

Question 6

Inflammation causes more cells to be recruited to the site of an infection via:

Answer 6

• Localised vasodilation and increased vascular permeability allowing cells to easily leak from the blood to the site of infection
• Activation of localised adhesion molecules on endothelial cells of the blood vessels. These “catch” cells of the immune system and cause a localised influx of cells

Question 7

Mast cells and basophils (degranulation)

Answer 7

These cells are activated by inflammation and release cytokines from their cytoplasmic granules — In a process known as degranulation

(5 main cytokines - outlined in another card)

Question 8

Cytokines released during mast cell degranulation (x5)

Answer 8

1) Prostaglandins - cause vasodilation and inhibit platelet aggregation (prevent clot formation)
2) Leukotrienes - Cause contraction of airway smooth muscle, attraction of neutrophils to the area of inflammation and increased vascular permeability
3) Heparin
4) Histamine
5) Enzymes

Question 9

What are Acute phase proteins:

Answer 9

Produced by the liver (stimulated by IL-6)

Act as opsonins

Question 10

6 Examples of acute phase proteins (produced by liver)

Answer 10

CRP (C-Reactive Protein)

Fibrinogen

Mannose-binding protein

C3

Hapatoglobulin

Serum Amyloid A

Question 11

Clotting system activation in inflammation:

Answer 11

Increased production of fibrinogen (acute phase protein released by the liver) + Activation of the clotting cascade

These both lead to the clotting of blood - helps limit the entry of pathogens into the bloodstream

Question 12

Kinin System in inflammation

Answer 12

Bradykinin causes contraction of airway smooth muscle, vasodilation, increased vascular permeability and pain.