L7 Acute Inflammation 2

Question 1

Cytokines

Answer 1

small protein made by a cell that affects the function of other cells


Question 2

Chemokines

Answer 2

small proteins that stimulate migration/ activation of cells

Question 3

Lipid mediators

Answer 3

products of AA metabolism

Question 4

Opsonization

Answer 4

coating of microbes with host proteins

Question 5

Chemical mediators of acute inflammation

What cells are cell derived mediators produced from?

Answer 5

Cell derived chemical mediators may be produced by (MELT) 
Mast cells
Endothelial cells
Leukocytes
Tissue macrophages

Question 6

Steps of removal

Answer 6

− Recognition and activation 

− Opsonisation 

− Phagocytosis: engulf invading tissue 

− Killing 

− Degradation of tissue to clean up the site 


Question 7

•Mediators of leukocyte activation and phagocytosis 


Answer 7

cytokines IFN-gamma

Question 8

•Mediators of microbe killing and degradation

Answer 8

NO

Question 9

•Recognize that leukocyte can induce tissue injury

2 circumstances

Answer 9

Effector mechanisms do not distinguish between offender and host
− Bystander tissue injury : prolong or exacerbate the consequences of injury 

− Misdirected (autoimmune disease or allergy)

Question 10

origins of chemical mediators

Cell derived mediators

Answer 10

Cell derived-made in a cell
Present in preformed secretory granules
Immediately released, synthesis in response to activation of NO and cytokines

Question 11

Activated leukocytes may release toxic products into the extracellular space
3 circumstances

Answer 11

− Normal function (eg of leukocytes that secrete neutral enzymes into the ECM, need to control secretion) 

− Frustrated phagocytosis 
release lysosome contents into extracellular space
− Ingestion of substance (urate crystals) damage phagolysosome 

Unable to digest properly, lead to the release of contents-damage nearby tissue

Question 12

Examples of cell derived mediators and their origins

Answer 12

Histamine-mast cells, basophils, platelets
Prostaglandins (mediator of pain and fever, AA metabolite)- mast cells, all leukocytes
Leukotrienes (AA metabolite)- mast cells, all leukocytes

Question 13

Examples of plasma derived mediators and their origins

Answer 13

Kinin system-bradykini

Coagulation-fibrinolysis system

Question 14

Plasma derived mediators
Complement system

3 pathways

Answer 14

Classical: microorganism binds to antibody, antibodies binds to something-> activation of complement-> more leukocytes coming to the site of injury

Alternative: complement directly binds to microorganism

Lectin: mannose binding lectin, host recognises mannose on microogranism-> activation of complement

Question 15

A preformed chemical mediators example

How it is released?

Answer 15

Histamine
Found in preformed granules
Released by a variety of stimuli

Release of histamine caused by 
•	C’, activation of complement
•	Physical injury

•	Binding of IgE, allergies
•	Protein, peptides and cytokines that are recognised by the MELT cells release contents of preformed granules-histamine