If a man has an attack of bronchi-ospasm it is necessary to reduce the effect of vagus on smooth muscles of bronchi. What membrane cytoreceptors should be blocked for this purpose?

Answer options

1. α-adrenoreceptors
2. N-cholinoreceptors
3. β-adrenoreceptors
4. M.cholinoreceptors
5. a- and β-adrenoreceptors

Explanation

M-choline receptors increase the muscle tonus of internal organs. Therefore, blocking this receptor will relieve the bronchospasm.