It goes down past the trachea and main bronchi to eventually reach the bronchioles - it's primary target.

经过气管和主支气管后，病毒最终到达其主要目标细支气管。

These conducting bronchioles receive oxygenated blood from the bronchial arteries of the systemic circulation.

这些传导性细支气管接受来自体循环的支气管动脉血液；动脉血含氧量丰富。

In bronchopneumonia, the infection can be throughout the lungs involving the bronchioles as well as the alveoli.

在支气管肺炎中，感染可以遍及肺部，包括细支气管和肺泡。

Sometimes, the mucus plugs end up acting like one way valves, allowing air to enter, but not escape the bronchioles.

有时，黏液栓会形成一个单向阀，空气能进去却出不来。

The respiratory zone includes the respiratory bronchioles and the alveoli.

呼吸区包括呼吸性细支气管和肺泡。

Asthma affects the respiratory system, particularly the smaller airways, such as the bronchi and bronchioles.

哮喘会影响呼吸系统，尤其是较小的气道，例如支气管和细支气管。

Air is conducted through smaller and smaller bronchioles for about 15-20 generations, and collectively they're known as conducting bronchioles, receiving O2 from bronchial arteries.

空气经过越来越小的细支气管传导大约15-20级；它们统称为传导性细支气管，从支气管动脉中获取O2。

Early on, minutes after the exposure to the allergen, smooth muscle around the bronchioles start to spasms and there is increased mucus secretion.

早期，在接触过敏原的几分钟后，细支气管周围的平滑肌开始痉挛，粘液分泌增多。

The smallest of the bronchial branches are called bronchioles. At the end of the bronchioles are clusters of air sacs called alveoli.

最小的支气管分支称为细支气管。在细支气管末端是称为肺泡的气囊簇。

Eventually the respiratory bronchioles ends when there are nothing but alveoli, and at that point the airway is called an alveolar duct rather than a respiratory bronchiole.

最终呼吸性细支气管结束于肺泡，此时气道被称为肺泡管，而不是呼吸性细支气管。