Hypersensitivity Type I & Shock

Question 1

type I hypersensitivity

Answer 1

• d/t various allergens

- IgE mediated

Question 2

initial mast cell sensitization

Answer 2

• allergen triggers T-helper cells –> T-helper cells release TH2 cytokines (mediators) –> TH2 activates B cells –> activated B cells = plasma cells
• plasma cells produce IgE —> IgE attaches to mast cell surface –> mast cells become sensitized

Question 3

re-exposures after sensitization

Answer 3

allergen binds to IgE Ab on mast cell to form IC –> mast cell degranulates (releases inflm mediators @ site of exposure) –> inflm mediators bind to diff receptors & cause allergic effects

Question 4

mast cell

Answer 4

type of WBC (similar to basophils) containing histamine-filled granules

Question 5

examples of Type I hypersensitivity

Answer 5

• allergy
• asthma
• anaphylaxis

Question 6

shock results in…

Answer 6

hypoperfusion & hypotension

Question 7

shock caused by..

Answer 7

cardiovascular failure (hypoxia)

Question 8

anaphylactic shock

Answer 8

• systemic hypersensitivity d/t severe allergic rxn
• mediators –> vasodilation & inc capillary permeability –> dec TPR & blood ineffectively distributed around body / fluid leaks into interstitial space out of vessels = dec blood vol –> hypoperfusion –> circulatory shock

Question 9

septic shock

Answer 9

d/t infection(s)

• vasodilatory mediators –> hypoperfusion & hypotension
• leads to multi-organ dysfunction/failure