Posterior basal segmental bronchus of right lung

The posterior basal segmental bronchus of the right lung, (B10) is the bronchus that supplies the posterior basal segment (S10) of the right lower lobe. It is one of the four (sometimes five) basal segmental bronchi arising from the basal trunk (basal segmental bronchus stem) of the right lower lobe, along with the medial basal (B7), anterior basal (B8), and lateral basal (B9) bronchi.

Anatomical features:

• Origin: B10 arises from the basal trunk bronchus of the right inferior lobe, typically as the most posterior and inferior branch. The most common branching pattern of the right inferior lobe is B6 (superior segment), followed by B7, B8, B9, and B10 from the basal trunk, seen in approximately 57% of cases.

• Course and territory: B10 courses posteriorly and inferiorly to supply the posterior basal segment (S10), which occupies the posteromedial and inferior portion of the right lower lobe, resting against the posterior chest wall and diaphragm.

• Subsegmental branches: B10 typically gives rise to subsegmental branches including B10a (posterior), B10b (lateral), and B10c (medial). The first subsegmental bronchus of B10 characteristically runs posteriorly.

• Vascular relationships: The corresponding segmental artery (A10) generally accompanies B10, lying toward the lung periphery relative to the bronchus. The segmental vein (V10) typically runs central (anterior or medial) to the bronchus.

Variations: Common variants include a shared trunk with the lateral basal bronchus forming a B9+10 common stem, absence of a separate B10 with its territory supplied by adjacent segments, and variable subsegmental branching patterns.