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The Respiratory System
Bronchial Branching and Airflow Control
Description
The bronchial tree carries air from the trachea into the lungs and helps control breathing. The trachea, or windpipe, connects the larynx to the bronchi. At the carina, the trachea splits into two primary bronchi. The right primary bronchus is wider, shorter, and more vertical than the left. Because of that shape, foreign ob...
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Transcript
在位于第五胸椎上界的气管隆凸处,气管分为左、右主支气管,分别通向相应的肺。右主支气管比左主支气管更短、更宽,且走向更垂直。
与气管类似,左右主支气管均由不完整的软骨环和纤毛假复层柱状上皮衬里构成。
进入肺部后,每条主支气管会分支为更小的叶支气管或次级支气管,每侧肺的每个肺叶均由一条支气管供气。
这些叶支气管进一步分支为更小的段支气管,分布于肺叶内的特定支气管肺段。
分支持续进行,形成细支气管,进而分支为终末细支气管,标志着支气管树传导区的末端。
细支气管含有克拉拉细胞(又称俱乐部细胞),这是一种无纤毛的柱状上皮细胞,具有防御吸入性毒素的作用,可能产生表面活性物质,并可发挥干细胞功能。
此外,支气管树的分...
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