2 Ac In Chemical mediator groups

Question 1

what’s role of chemical mediators in the body?

Answer 1

modulate the inflammatory response

Question 2

name 6 examples of chemical mediators

Answer 2

• serotonin
• histamine
• complement
• bradykinin
• prostaglandin
• leukotrienes

Question 3

How long do chemical mediators typically last in the body ?

Answer 3

they are short-lived

Question 4

What are the 2 sources of chemical mediators ?

Answer 4

• endogenous
• endotoxin

Question 5

where are endogenous chemical mediators of inflammation derived from ?

Answer 5

• plasma proteins
• leukocytes
• local tissues

Question 6

where are exogenous chemical mediators of inflammation derived from ?

Answer 6

endotoxins from gram negative bacteria

Question 7

What does every chemical mediator have ?

Answer 7

an inhibitor

Question 8

What’s function of histamine as a chemical mediator ?

Answer 8

a role in the inflammatory response by causing vasodilation and increasing vascular permeability

Question 9

endogenous chemical mediators involved in acute inflammation ?

Answer 9

1. vasoactive amines e.g. histamine and serotonin
2. vasoactive peptides e.g. bradykinin
3. chemokines and cytokines e.g. IL-1, TNF
4. arachidonic acid metabolites e.g. prostaglandins, leukotrienes such as LTB4
5. nitrix oxide

Question 10

What chemical mediators facilitate the vascular phase of acute inflammation ?

Answer 10

1) Vasoactive amines e.g., histamine, seratonin
2) Arachidonic acid metabolites e.g., prostaglandins
3) Bradykinin
4) Others e.g., NO

Question 11

What are the three inter-related enzymatic cascade systems involved in producing inflammatory mediators in the liver ?

Answer 11

1) Coagulation/fibrinolytic system = this forms thrombin + fibrin
2) Kinin systems = produces bradykinin (vasoactive peptide) from plasma protein kininogens
3) Complement system = e.g., C5a, MAC, C3b

Question 12

The complement system is activated by a variety of mechanisms… what are they?

Answer 12

1) Proteolytic enzymes from necrotic cells
2) Antigen-antibody complexes in infection
3) Gram negative bacteria1
4) Products of kinin and fibrinolytic systems

Question 13

The complex cascade generates… C3b, C5a, C5-9 complex

What is the role of C3b? explain what they are

Answer 13

C3b functions as an opsonin

Opsonins are extracellular proteins that, when bound to substances or cells, induce phagocytes to phagocytose the substances or cells with the opsonins bound

Question 14

The complex cascade generates… C3b, C5a, C5-9 complex

What is the role of C5a?

Answer 14

C5a attracts neutrophils (chemoattractant)

Question 15

Name some chemical mediators which facilitate vasodilatation

Answer 15

Histamine
Prostaglandins
Bradykinin
NO

Question 16

Name some chemical mediators which facilitate increased vascular permeability

Answer 16

Histamine
Bradykinin
NO
Leukotrienes
C5a + C5b