- Anatomic, functional, surgical sectors of lung with each segment aerated by Segmental/Tertiary Bronchus.
- Each segment has a tertiary bronchus, segmental artery, lymph vessels & autonomicnerves but segmental veins lie in the connective tissue b/w adjacent BPS.
- Thus one segment is drained by more than one vein & one vein drains more than one segment.
1) Knowledge of bronchopulmonary segments(BPS) essential for precise interpretation of radiographs or other lung images.
2) Surgical: tumors or abscesses tend to localize in the BPS & may require surgical intervention.
A diseased Segment can be removed surgically. The Surgeon works along the segmental veins to isolate a particular segment & carry out Segmentectomy/Segment Removal.
3) Aspiration: a) Supine position : Superior Segment of Lower Lobe
b) Standing position : Posterior Basal Segment of Lower Lobe of Right Lung
4) TB : Apical & Posterior segments of upper lobes d/t high ventilation perfusion ratio with elevated alveolar pO2 w.r.t other zones.
5) Cancerous lesion : Anterior segment of Right Upper Lobe
6) Lung Abscess : Posterior segment if upper lobe is involved. Superior, Posterior Basal Segment of Lower Lobe. Especially on Right Lung because of more vertical bronchus.
8) Infections never cross Intersegmental Septa & are restricted to one BPS except TB & Cancer.
9) At Carina (Trachea divides into 2 bronchi) Right Bronchus is tngulated at 25° & Left Bronchus at 45°.