Left superior lobar bronchus
Bronchus lobaris superior sinister
The upper of the two branches of the left main bronchus, supplying the upper lobe of the left lung and its lingula.
At a glance
- English
- Left superior lobar bronchus
- Latin (TA2)
- Bronchus lobaris superior sinister
- System
- Respiratory
- Region
- Thorax
- Side
- Single, on the midline
About the left superior lobar bronchus
The left superior lobar bronchus is a secondary bronchus. It arises from the front and side of the left main bronchus inside the hilum of the left lung, after the main bronchus has passed beneath the left pulmonary artery. The artery hooks over the main bronchus and then lies behind and above the start of this branch, so on the left there is no airway above the artery: the upper-lobe bronchus, like all the others on this side, is hyparterial.
It runs forwards and outwards for about a centimetre and then divides into two stems. The upper stem, sometimes called the upper division, turns upwards and splits into the apicoposterior and anterior segmental bronchi, which supply the apex and front of the lobe. The lower stem, the lingular bronchus, runs forwards and down and splits into the superior and inferior lingular segmental bronchi. The lingula, the tongue-shaped lower front part of the upper lobe, is the left-sided counterpart of the right middle lobe, and its bronchus is matched to the right middle lobar bronchus.
The structure of its wall follows the general bronchial plan. Irregular plates of hyaline cartilage replace the regular rings of the trachea, smooth muscle encircles the lumen, and a ciliated, mucus-producing lining keeps it clean. It conducts air only.
Clinically, blockage of this bronchus collapses the whole upper lobe, which on a frontal X-ray produces a veil-like haze over the left lung. Infections of the lingula can blur the left heart border, since that part of the lung sits against the heart.
Function and supply
- Begins at
- The anterolateral wall of the left main bronchus within the hilum of the left lung.
- Ends at
- Divides into an upper stem (apicoposterior and anterior segmental bronchi) and the lingular bronchus (superior and inferior lingular segmental bronchi).
- Function
- Carries air to and from the upper lobe of the left lung, including the lingula.
- Nerve supply
- Pulmonary plexus (vagal and sympathetic fibres).
- Blood supply
- Left bronchial arteries from the descending aorta.
Anthromica
See the left superior lobar bronchus where it really sits, with every layer of the body around it.
- Every layer, one body. Peel from muscle to bone, nerve, vessel and organ, and turn it any way.
- English and Latin. Every structure named the way your exam names it.
- Quiz until it sticks. Short drills on the structures you keep missing.
Free to start. No card.
