Lobar bronchi
Bronchi lobares
Also known as: secondary bronchi
The second-generation airways, one supplying each lobe: right superior, middle and inferior; left superior (including the lingular bronchus) and inferior.
Overview
On the right, the superior lobe bronchus arises from the main bronchus above the pulmonary artery; the bronchus intermedius then gives the middle lobe bronchus anteriorly and continues as the inferior lobe bronchus, whose first branch posteriorly is the superior segmental bronchus (B6). On the left, the main bronchus divides into superior and inferior lobe bronchi; the superior lobe bronchus gives a lingular bronchus that is the counterpart of the right middle lobe bronchus.
Lobar bronchi have plate-like cartilage and complete smooth muscle layers, and each enters its lobe together with the corresponding lobar artery.
- Location
At and just within the hila of the lungs.
Parts & subdivisions
- Right superior, middle and inferior lobe bronchiSupply the three right lobes.
- Left superior lobe bronchus (with lingular bronchus) and left inferior lobe bronchusSupply the two left lobes; the lingula corresponds to the right middle lobe.
Function
- Distribute air to individual lobes.
Clinical significance
Lobar collapse
Obstruction of a lobar bronchus by tumour, mucus plug or foreign body causes collapse with characteristic radiographic signs (e.g. left lower lobe collapse gives a triangular "sail" opacity behind the heart; right upper lobe collapse with a hilar mass gives the "Golden S" sign).
Right middle lobe syndrome
The middle lobe bronchus is long, narrow and surrounded by lymph nodes, so it is prone to extrinsic compression and recurrent collapse or infection.
Compiled from standard anatomy and physiology references — see the Respiratory System sources. For education only; not medical advice.