Bronchus
Airway in the respiratory tract

A bronchus is a passage or airway in the lower respiratory tract that conducts air into the lungs. The first or primary bronchi to branch from the trachea at the carina are the right main bronchus and the left main bronchus. These are the widest bronchi, and enter the right lung, and the left lung at each hilum. The main bronchi branch into narrower secondary bronchi or lobar bronchi, and these branch into narrower tertiary bronchi or segmental bronchi. Further divisions of the segmental bronchi are known as 4th order, 5th order, and 6th order segmental bronchi, or grouped together as subsegmental bronchi.
The bronchi, when too narrow to be supported by cartilage, are known as bronchioles. No gas exchange takes place in the bronchi.
Begin with the source’s own compact description: “Bronchus” is airway in the respiratory tract. The dossier treats that line as a proposition to test through Bronchus, Airway and respiratory, not as a finished interpretation.
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Named sources, stable identifiers and responsible institutions provide the strongest route from overview to verifiable evidence. The source revision retrieved here is dated Feb 26, 2026.
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This entry incorporates text from “Bronchus” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.