Airway Tone

Question 1

What does the parasympathetic NS do and what is it mediated by?

Answer 1

Bronchoconstriction

Vagus nerve

Question 2

What neurotransmitter is released by the parasympathetic NS and what does it act on and do?

Answer 2

Acetyl choline acts on muscarinic (M3) receptors on airways smooth muscle

Question 3

What does the sympathetic NS do and what is it mediated by?

Answer 3

Bronchodilates

Mediated by sympathetic chain

Question 4

What neurotransmitter is released by the sympathetic NS and what does it act on and do?

Answer 4

Noradrenaline (after sympathetic stimulation) acts on adrenal glands to release adrenaline
Adrenaline acts on beta 2 adrenoreceptors on airway smooth muscle

Question 5

What are resp problems & difficulty breathing treated by?

Answer 5

Bronchodilation

Question 6

What drugs cause bronchodilation?

Answer 6

Increase sympathetic, B2 agonists - salbutamol

Decrease parasympathetic, M3 antagonists - ipa/tiotropium

Question 7

What do agonists both have?

Answer 7

Affinity and efficacy for binding to receptors

Question 8

What do antagonists have?

Answer 8

Affinity but no efficacy