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。

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。

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。

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。

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。

The conducting zone, which includes everything from the nose to the smallest bronchioles, moves air into and out of the lungs.

传导区，包括从鼻子到最小的细支气管的所有结构，运输气体进出肺。

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。

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。

After the first three generations of bronchi, however, the airways become more narrow, called bronchioles - 'little bronchi', and these can stay open without the need for cartilage.

然而，前三级支气管的下级：气道变得更狭窄，称为细支气管；这些气管可以保持开放而不需要软骨。

Since the bronchioles are smaller, even a slight increase in mucus can lead to airway obstruction, so this contributes to the majority of the air trapping.

因为细支气管管径更小，即使少量黏液增加也会使其阻塞，大部分气体滞留的原因即此。

The respiratory zone includes the respiratory bronchioles and alveoli and moves the respiratory gases, that is oxygen and carbon dioxide, in and out of the blood.

呼气区包括呼吸性细支气管和肺泡，它们运送氧气和二氧化碳这些参与呼吸的气体进出血液。

Finally, in the bronchi, but not the bronchioles, there is also a layer of cartilage below the submucosa which stiffens the bronchus and helps to keep it open.

最后，在某些支气管中，黏液下层之下还有一层软骨；这些软骨可以使支气管变硬并且保持开放。

During inhalation, air reaches your lungs by traveling down your trachea, then it continues through the bronchi and the bronchioles and ends up in the alveoli.

吸气时，空气通过气管进入肺部，然后继续穿过支气管和细支气管，最后进入肺泡。

The lower respiratory system begins with the larynx, or voice box, and includes the trachea, or wind pipe, bronchi, bronchioles, and alveoli within the lungs.

下呼吸系统始于喉、也可称音箱，并且包括气管，也可称风管，支气管，细支气管和肺内的肺泡。

Now the walls of the conducting bronchioles are similarly lined by ciliated columnar cells and mucus secreting goblet cells, as well as a new cell type called club cells.

传导性支气管壁上也有纤毛柱状细胞、分泌粘液的杯状细胞，还有棒状细胞。

So if we take a look at the lungs, you've got the trachea which branches off into the right and left bronchi and then continues to branch into thousands of bronchioles.

所以，如果我们看一下肺：这是气管，它会分支到右和左支气管，然后继续延伸到成千上万的细支气管。

To make matters worse, though, smoking makes the cilia short and less mobile, making it harder to move mucus up and out of bronchioles towards the back of the throat to get swallowed.

更糟糕的是，吸烟使纤毛变短，移动幅度更小，使之更难将黏液排送出细支气管，未能抵达咽部被吞咽。