Kenny and the bees

1
Kenny and the bees

• By
• Kathleen Meehan
• Janna Ott
• Heather Wright
• Allison King

2
The Question at hand

• The first time Kenny is stung by a bee, he gets
  some relatively minor itching and edema at the
  site. However, the second time hes stung,
  instead of the normal immune response which works
  to remove the foreign antigens, Kenny has a
  severe allergic reaction.
• Briefly describe the pathogenesis of itch
• Describe the combined action of mast cells and
  the immune system during sensitization
• Explain why Kenny was prescribed an Epi-pen to
  use the next time he has an allergic reaction.

3
Those dirty pathogens The pathogenesis of itch

• The body responds to the venom injected by the
  bee by excreting fluid from blood to flush out
  venom components
• Melittin in bee venom activates a signal
  transduction pathway that stimulates pain
  receptors and promotes inflammation
• pain, swelling, redness, itching and a wheal
  surround the wound

4
Anaphylactic shock

• Depending on location and number of stings,
  serious allergic reaction can cause Anaphylactic
  Shock which can be life-threatening

5
Mast cells you make Kenny cry

• Venom components circulating in the body combine
  with antibodies associated with mast cells
• Mast cell release histamine
• Leakage of fluid out of the blood and into body
  tissues
• Blood pressure drops
• Fluid builds up in lungs
• Chest wheeze, nausea, vomiting, and
• confusion are also common.

6
Sensitization The Second Sting

• If this is not the first time that the person has
  been stung by that species of insect, it is
  likely that the immune system will recognize the
  venom and enhance the disposal procedure
• This can lead to very large swelling around the
  sting site or in a whole portion of the body

7
The Epi-Pen Prescription

• Anaphylaxis, if treated in time, usually
• can be reversed by the effects of epinephrine
• An auto-injector (Epi-Pen) can be used for this
  immediate epinephrine injection
• Epinephrine works on the sympathetic nervous
  system, acting on both alpha and beta receptors
• Alpha adrenergic receptors counters vasodilation
  and increased vascular permeability, thus
  reducing loss of plasma fluid and hypotension
• Beta receptors causes bronchial smooth muscle
  relaxation which alleviates wheezing and
  shortness of breath

8
The Dreaded Test Analogy

• Our first Physiology test
• Normal studying tactics (reading notes and book)
• "that was not a good experience... Study better
  next time
• Alarm at the memory of the first exam (sting) and
  over studying (over immune response)

• The original bee sting
• The original immune response (mast cells and
  creation of antibodies)
• The response/outcome
• The second sting response

9
Questions?????