Smooth muscle along the trachea and the first few branches of bronchi have beta 2 adrenergic receptors.

气管和初级支气管分支肌上，都有β2。

Going back to that turkey, when you're running, the sympathetic nerves stimulate those beta 2 adrenergic receptors and increase the diameter of the airways.

再来看逃离大鹅例子：当我们在奔跑时，交感神经系统激动β2，使气道扩张，以吸入更多氧气。

Class 2 beta blockers These drugs bind to beta-1 adrenergic receptors and block the sympathetic influences that act through these receptors.

第二类是β阻滞剂。这类药物与β-1肾上腺素结合，阻断交感神经作用于这些产生影响。

Also, medications might be given, to help reduce pain, reduce stone formation, like potassium citrate, and to help stones pass through, like alpha adrenergic blockers and calcium channel blockers.

亦可通过给药（如柠檬酸钾）来减轻疼痛，减少结石生成；以及用肾上腺素α阻断剂以及钙离子通道阻断剂，促进结石排出。