Left main bronchus
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108945026
2007-02-18T00:00:13Z
Caerwine
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restub
{{Infobox Anatomy |
Name = {{PAGENAME}} |
Latin = bronchus principalis sinister |
GraySubject = 237 |
GrayPage = 1085 |
Image = Illu_conducting_passages.jpg |
Caption = Conducting passages. |
Image2 = Gray961.png |
Caption2 = Front view of cartilages of larynx, trachea, and bronchi. |
System = |
MeshName = |
MeshNumber = |
DorlandsPre = b_23 |
DorlandsSuf = 12198348 |
}}
The '''left main bronchus''' (or '''left primary bronchus''', or '''left principal bronchus''') is smaller in caliber but longer than the [[Right main bronchus|right]], being nearly 5 cm long. It enters the root of the [[left lung]] opposite the sixth [[thoracic vertebra]].
It passes beneath the [[aortic arch]], crosses in front of the [[esophagus]], the [[thoracic duct]], and the [[descending aorta]], and has the left [[pulmonary artery]] lying at first above, and then in front of it.
The left bronchus has no [[eparterial branch]], and therefore it has been supposed by some that there is no upper lobe to the left lung, but that the so-called upper lobe corresponds to the middle lobe of the [[right lung]].
==Additional images==
<gallery>
Image:Lungs anatomy.png|Anatomy of lungs.
Image:Gray622.png|The tracheobronchial lymph glands.
Image:Gray1032.png|The position and relation of the esophagus in the cervical region and in the posterior mediastinum. Seen from behind.
</gallery>
==External links==
* {{eMedicineDictionary|left+main+bronchus}}
* {{SUNYAnatomyFigs|19|08|02}} - "The divisions of the bronchus."
{{Gray's}}
{{respiratory-stub}}
{{Lung}}