Type 1 Hypersensitivity

Question 1

Shock

Answer 1

Failure to maintain an adequate cardiac output

Question 2

Hypovolemic shock

Answer 2

Haemorrhage, severe fluid loss

Question 3

Obstructive shock

Answer 3

pulmonary embolus or tamponade

Question 4

Cardiogenic shock

Answer 4

MI, heart failure, myocarditis

No obstruction, but cannot pump with enough strength

Question 5

Distributive

Answer 5

Leakage of fluid from vascular to interstitial compartments because of increase permeability
Septic, anaphylactic, neurogenic

Question 6

Clonal Deletion

Answer 6

Removal through apoptosis of B cells and T cells that have expressed receptors for self before developing into fully immunocompetent lymphocytes

Question 7

Central tolerance

Answer 7

lymphocyte deletion

Question 8

Peripheral tolerance

Answer 8

T-reg cells

Question 9

IgG MOA

Answer 9

Block pathogen binding, activate complement and opsonise antigen for phagocytes

Question 10

IgG location

Answer 10

Secreted by plasma cells in blood

Able to cross placenta

Question 11

IgM MOA

Answer 11

Block pathogen binding + activate the complement (early stages of immunity)

Question 12

IgM location

Answer 12

Surface of B cell

In blood

Question 13

IgA MOA

Answer 13

Blocks pathogen binding (neutralisation)

Question 14

IgA location

Answer 14

Found in mucous, saliva, tears + breast milk

Question 15

IgE MOA

Answer 15

Activates mast cells

Protects against parasitic worms

Question 16

IgD MOA

Answer 16

Part of B cell receptor

Activates basophils and mast cells

Question 17

Activation of Mast Cells + basophils

Answer 17

Cross-linking of surface IgE by antigen
Via complement proteins C3a and C5a
Via nerves: axon reflex of sensory nerves, substance P
Direct contact through PAMP

Question 18

Atopy

Answer 18

inherited predisposition to make IgE to common environment antigens

Question 19

Histamine

Answer 19

Increase in post-capillary venules, vasodilation of arterioles, itch and contraction of smooth muscle

Question 20

Leukotrienes

Answer 20

Increase in permeability of post-capillary venules as well as chemotaxis

Question 21

Local Type 1 Hypersensitivity

Answer 21

Asthma
Atopic Eczema
Urticaria
Angiodema

Question 22

Systemic Type 1 Hypersensitivity

Answer 22

Anaphylactic shock

Question 23

Anaphylactic Shock

Answer 23

Drop in BP
Urticaria
Angioedema
Bronchoconstriction
Nausea and vomiting
Headache
Confusion
Loss of consciousness
Impending doom

Question 24

Anaphylaxis acute treatment

Answer 24

Intramuscular adrenaline 500 micrograms
O2 high flow
Antihistamines
Glucocorticosteroids (200mg hydrocortisone)
Fluids

Question 25

Anaphylactoid shock

Answer 25

Non allergic
same symptoms but IgE not involved
Mast cells + basophils activated by another method