Inflammatory Cells

Question 1

what are mast cells?

Answer 1

cellular bags of granules found in large numbers in the skin and linings of the GI and respiratory tract

Question 2

when are mast cells activated?

Answer 2

physical injury, chemical agents, immunologic and infectious means

Question 3

what does the activated mast cell synthesize?

Answer 3

inflammatory mediators derived from plasma membrane lipids such as platelet activating factor, prostaglandin D2 and leukotrienes as well as cytokines and growth factors which results in long term response

Question 4

what is histamine?

Answer 4

is a potent vasodilator that causes increased vascular permeability through retraction of endothelial cells
- also causes smooth muscle to contract causing bronchoconstriction when stimulated in the bronchi

Question 5

what are leukotrienes?

Answer 5

functions are similar and complementary to that of histamine
- more potent and stimulate slower and more prolonged effects compared to histamine
- cysteine leukotrienes (ex. LCT4, LTD4, LTE4) cause slow and sustained constriction of the bronchioles

Question 6

what is prostaglandin D2?

Answer 6

causes vasodilation, increased vascular permeability and bronchoconstriction

Question 7

what are chemotactic chemokines?

Answer 7

are cytokines that attract immune cells, they primarily function to attract leukocytes

Question 8

what are cytokines?

Answer 8

defined as “small signalling proteins secreted by immune cells that modulate the function of other cells”
- TNF alpha, IL-1, 4, 5, 8, 13)

Question 9

what are the key mediators in the pathogenesis of asthma?

Answer 9

TNF-alpha, IL-4, 5,8 and 13

Question 10

what is the function of TNF-alpha?

Answer 10

increased the activation and migration of inflammatory cells (specifically eosinophils and neutrophils) and contributes to airway remodelling
- also causes endothelial cells to express adhesion molecules

Question 11

what is the function of TNF-alpha and IL-1 together?

Answer 11

alter muscarinic receptor function resulting in increased levels of acetylcholine which causes bronchial smooth muscle contraction and mucus secretion

Question 12

what are the T helper 2 cytokines?

Answer 12

IL-4, 5, 8 and 13

Question 13

what is the function of IL-4?

Answer 13

stimulates activation, proliferation and production of antigen-specific, IgE by B cells

Question 14

what is the function of IL-5?

Answer 14

activates and promotes eosinophils activity

Question 15

what is the function of IL-8?

Answer 15

causes a more exaggerated inflammatory response through activation of basophils, neutrophils and eosinophils

Question 16

what is the function of IL-13?

Answer 16

impairs the clearance of mucus, contributes to bronchoconstriction and increases fibroblast secretion

Question 17

what is the function of PAF (platelet activating factor)?

Answer 17

induces platelet aggregation, increases vascular permeability through endothelial cell retraction, activates neutrophils and is a potent eosinophil chemoattractant

Question 18

what does PAF cause in the respiratory system?

Answer 18

causes bronchospasm, eosinophil infiltration and non specific bronchial hyperreactivity

Question 19

what were cysteinyl leukotrienes originally called?

Answer 19

“slow reacting substance of anaphylaxis” due to their effect on bronchial smooth muscle of slow and prolonged contraction and hence bronchoconstriction

Question 20

what are the leukocytes?

Answer 20

macrophages, eosinophils, neutrophils, lymphocytes and basophils

Question 21

what are neutrophils, eosinophils and basophils also known as?

Answer 21

granulocytes

Question 22

which leukocytes are on the scene first and the predominant phagocytes in the early inflammatory phase?

Answer 22

neutrophils

Question 23

which leukocyte is a T and B cell?

Answer 23

lymphocytes

Question 24

how are basophils similar to mast cells?

Answer 24

they bind to IgE which is secreted by plasma cells and release histamine and mediators of inflammation such as IL-4

Question 25

what leukocyte arrives after neutrophils and arrive in the late phase?

Answer 25

macrophages