Segmental bronchi
Bronchi segmentales
Also known as: tertiary bronchi
Third-generation airways, each ventilating one bronchopulmonary segment — ten in the right lung and typically eight to ten in the left.
Overview
Segmental bronchi are numbered B1–B10 and named after the segments they supply. Right: superior lobe — apical (B1), posterior (B2), anterior (B3); middle lobe — lateral (B4), medial (B5); inferior lobe — superior (B6), medial basal (B7), anterior basal (B8), lateral basal (B9), posterior basal (B10). Left: superior lobe — apicoposterior (B1+2), anterior (B3), superior lingular (B4), inferior lingular (B5); inferior lobe — superior (B6), anteromedial basal (B7+8), lateral basal (B9), posterior basal (B10).
Each segmental bronchus travels in the centre of its segment with a segmental branch of the pulmonary artery, while tributaries of the pulmonary veins run in the intersegmental planes — the surgical guide for segmentectomy. Beyond the segmental bronchi, smaller subsegmental bronchi divide repeatedly before becoming bronchioles.
- Location
Within the lobes, radiating from the lobar bronchi.
Function
- Distribute air to individual bronchopulmonary segments, which are independent functional and surgical units.
Clinical significance
Bronchoscopic and postural anatomy
Knowing segmental anatomy allows bronchoscopists to sample specific segments and physiotherapists to position patients so that gravity drains each segment.
Compiled from standard anatomy and physiology references — see the Respiratory System sources. For education only; not medical advice.