Stening 
Distribution anomaly: tracheal bronchus. An additional bronchus is born in the right side wall and heads to the homolateral upper lobe. Depending on its location, the tracheal bronchus can cause exclusive atelectasis of the superior lobe during anesthetic intubation.
Distribution anomaly: Tracheal bronchus. Part of the right upper lobe is ventilated thanks to a bronchus that has shifted during the embryonic phase of lung development so that it is born directly from the trachea. Sometimes, this bronchus only leads to the apical segment of the right upper lobe and is, in these cases, a “supernumerary” bronchus. It can be … Read more
Sometimes the atrophy of the mucosa is so marked that it allows to explore bronchi of 4th and 5th order.
Another variant very common in the lower left lobe, its division into two small trunks containing the three basal.
Accustomed distribution “in line” of the three left basal: anterior (LB8) here at 12 o’clock and partially hidden by the bronchial wall, medial (LB9) in the center and posterior segmental (LB10) below.
Close view at hour 3 of the entrance to the apical segment of the left upper lobe (LB6). In its natural position, it is the first one that appears when leaving the upper left lobe bronchus.
A view of the lingular bronchus and its divisions in superior (LB4) at hour 11 and to its right the inferior (LB5).
From left to right: segmental medial (RB5) and lateral (RB4) of the middle lobe bronchus. Division between the anterior segment (LB3) at hour 3 and the apicoposterior (LB1+2) at hours 8 and 10) of the left upper lobe.
Entrance to the left upper lobe. In the background on the right, the bronchus of the lingula and on its left, at 10 o’clock, the small bronchial passage culminate, until its division, which is not observed here, in anterior segmental (LB3) and apicoposterior (LB1+2).
Image of the secondary carina that separates the upper and lower left lobular. The area is also called a crossroads or “carrefour”.