The Chemical Mediators Of Inflammation

Question 1

Which 2 categories can chemical mediators of inflammation be group into?

Answer 1

Locally generated (produced at injured site)
Those originating from plasma

Question 2

Give examples of locally generated signals

Answer 2

• Histamine
• Serotonin
• Prostaglandins
• Leukotriens
• Platelet activating factor
• ROS
• NO
• chemokines
• cytokines (TNF, IL1 etc)

Question 3

Describe the origin and function of: Histamine

Answer 3

Released from mast cell granules

Important role in initiating acute inflammation, causing vasodilation and increased permeability

Question 4

Describe the origin and function of: Serotonin

Answer 4

Produced by platelets

Has a similar role to histamine

Question 5

Describe the origin and function of: Prostaglandins and Leukotriens

Answer 5

Originate from arachidonic acid and released by mast cells and other leukocytes
They increase permeability, cause vasodilation, promote leukocyte adhesion and chemotaxis

Question 6

Describe the origin and function of: Platelet activating factor

Answer 6

Released from leukocytes and mast cells

Causes vasodilation, increased permeability, leukocyte adhesion and chemotaxis

Question 7

Describe the origin and function of: ROS

Answer 7

Produced by leukocytes in the tissues

Has a role in microbial killing and causes tissue damage

Question 8

Describe the origin and function of: NO

Answer 8

Generated by endothelial cells and macrophages

Has a role in vasodilation and in microbial killing

Question 9

Describe the origin and function of: Chemokines

Answer 9

Released from mast cells and leukocytes

Promote leukocyte activation and chemotaxis

Question 10

Describe the function of: Cytokines

Answer 10

• promote endothelial activation

- mediate the changes that occur on the cell surface of endothelial cells

Question 11

Give examples of signals that get into the tissue from plasma

Answer 11

• Kinins and proteases

- Complement

Question 12

What are kinins and proteases?

Answer 12

Short peptides involvedd in vasodilation and increased permeability; proteases are also involved in leukocyte recruitment

Question 13

What are anaphylotoxis? Describe their role

Answer 13

These are components of the complement cascade, produced by the alternative pathway (e.g. C3a and C5a). They work as potent chemoattractants and recall neutrophils