9.6.1. Bronchopulmonary Segments


The bronchopulmonary segments are the smallest notable subdivisions of each lung lobe. They are all 'roughly' pyramid-shaped with the apex of the pyramid facing the lung root (medial) and the base facing the lateral costal surface of the lung (although this is kind of hard to imagine!). These segments are separated by connective tissue and each segment is supplied by a named tertiary (or segmental) bronchus and a tertiary (or segmental) bronchial artery. Each segment is also drained by a segmental vein that lies in the connective tissue between segments. Importantly, a bronchopulmonary segment is the smallest functionally independent area of the lung that can be isolated without affecting adjacent regions, i.e. in some instances, specific damage to one segment will affect only that one segment. The names of each segment might seem strange and a bit illogical, but use the list below and the accompanying diagram to help you understand. Also try to use a 3D model / 3D app to help you. If you can visualise this structure in your mind, you’re doing well! The corresponding tertiary bronchi are shown on the next page.

Naming the Bronchopulmonary Segments

The names of the bronchopulmonary segments are as follows:

Right lung (upper lobe)

- Apical
- Anterior
- Posterior

Right lung (middle lobe)

- Medial
- Lateral

Right lung (lower lobe)

- Superior
- Anterior basal
- Medial basal
- Lateral basal
- Posterior basal

Left lung (upper lobe)

- Apico-posterior
- Anterior
- Superior lingular
- Inferior lingular

Left lung (lower lobe)

- Superior
- Anteromedial basal
- Lateral basal
- Posterior basal

Total no. of segments on right: 10.
Total no. of segments on left: 8.