inflammation 3

Question 1

chemical mediators of inflammation

Answer 1

cell derived mediators
vasocactive amines-histamine and seratoin
acrachidonic acid metabolites
nitric oxide (NO)
cytokines
plasma derived mediators
complement system

Question 2

histamine

Answer 2

present in a PREFORMED state in mast cells, basophils and platelets in cytoplasmic granules-can be released instantly as needed and mast cells typically are found in connective tissue near blood vessels
histamine is released (Degranulation) in response to-physical injury, immune reaction and presence of complement fragments C3a and C5a

Question 3

action of histamine

Answer 3

dilatation of arterioles
increased vascular permeability of venule
causes endothelial contraction in venules

Question 4

seratonin

Answer 4

also known as 5-hydroxytrptamine
preformed in platelets-released in response to platelet aggregation
actions are similar to histamine in acute inflammation

Question 5

arachidonic acid metabolites

Answer 5

degradation of cell membrane phospholipids by phospholipases yields AA

Question 6

eicosanoids

Answer 6

product of aa metabolism
regulate inflammation and gemostasis

Question 7

two primary classes of inflammatory metabolites

Answer 7

prostaglandins
leukotrienes

Question 8

arachidonic acid metabolites

Answer 8

corticosteroids inhibit the action of phospholipases and the production of AA

Question 9

prostaglandins are produced by cyclooxygenases

Answer 9

cox-1 constitutively expressed
cox-2 inducible
include PGE2, PGD2, PGF2a, PGI2 (prostacyclin and TXA (thromboxane)

Question 10

aspirin and NSAID

Answer 10

inhibit cyclooxygenases (cox1 and cox2) and inhibit synthesis of prostaglandins-cox2 selective inhibitor
the activity of lipoxygenases is not affected by NSAID

Question 11

lipoxygenase pathway

Answer 11

lipoxygenase-enzyme that produces leukotrienes and lipoxin from AA
leukotrienes-chemotactic for leukocytes
vascular effects: vasocontraction and increase vascular permeability
lipoxin-lipoxin inhibit inflammation-inhibit leukocyte recruitment and cellular components of inflammation

Question 12

nitric oxide

Answer 12

produced by endothelial cells, macrophages neurons
synthesized by nitric oxide synthase

Question 13

Nitric oxide two functions in inflammation

Answer 13

vasodilation (contributes to vascular reaction)
inhibits cellular inflammatory response-reduces platelet aggregation and adhesion (Anti-inflammatory)
inhibit leukocyte recruitment (anti-inflammatory)
as a free radical kills microbes

Question 14

cytokine mediators

Answer 14

cytokines-polypeptides produce primarily by macrophages and lymphocytes
primary action is modulation of activities of other cells
the main cytokines involved in acute inflammation are IL-1 and TNF (tumor necrosis factor)

Question 15

plasma protein mediators

Answer 15

complement-defense against microbes-formation of MAC (membrane attack complex)
complement activation causes-increase vascular permeability, chemotaxis, opsonization
main components are present as inactive plasma precursors (C1-9)

Question 16

activation of complement

Answer 16

classical pathway
alternative pathway
lectin pathway

Question 17

classical pathway

Answer 17

reaction with IgG or IgM containing antigen-antibody complex

Question 18

alternative pathway

Answer 18

contact with microbial surfaces and polysaccharides

Question 19

lectin pathway

Answer 19

plasma mannose-binding lectin binds to microbes

Question 20

plasma proteases-complement

Answer 20

the initial steps in complement activation leads to formation of an enzyme-C3 convertase wich cleaves C3

Question 21

C3 cleavage leads to

Answer 21

release of C3a (Anaphylatoxin)
covalent attachment of C3b (initiates formation of C5 convertase)
formation of C5-9 MAC

Question 22

complement derived mediators (formed during cleavage)

Answer 22

C3a and C5a-failitate histamine release from mast cells (Vasodilate, increase permeability-aka anaphylatoxin

Question 23

C5a

Answer 23

activates lipoxygenase pathway of AA metabolism in neutrophil and monocytes
chemotactic for neutrophils, monocytes eosinophils and basophils