Which of the following is more effective in producing bronchodilation?
A) Acetylcholine
B) Nicotine
C) Muscarine
D) Norepinephrine
E) Thyroxine

Question

Quizplus · Accepted Answer

Norepinephrine is a sympathetic nervous system neurotransmitter that binds to beta-2 adrenergic receptors on bronchial smooth muscle, causing their relaxation and resulting in bronchodilation. Acetylcholine, nicotine, and muscarine are all parasympathetic nervous system neurotransmitters that bind to muscarinic receptors on bronchial smooth muscle, causing their contraction and resulting in bronchoconstriction. Thyroxine has minimal direct effect on bronchodilation.

Which of the Following Is More Effective in Producing Bronchodilation