Bronchopulmonary segments

Bronchopulmonary segments are subdivisions of the lungs, each supplied by a segmental (tertiary) bronchus and a corresponding branch of the pulmonary artery. They are functionally and anatomically distinct, separated by connective tissue septa, and can be surgically resected without affecting adjacent segments. Here’s a breakdown of bronchopulmonary segments in each lung:

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Right Lung

The right lung has three lobes (upper, middle, and lower), with a total of 10 bronchopulmonary segments:

1. Upper Lobe (3 segments)

   • Apical (S1)
   • Posterior (S2)
   • Anterior (S3)

2. Middle Lobe (2 segments)

   • Lateral (S4)
   • Medial (S5)

3. Lower Lobe (5 segments)

   • Superior (S6) (also called apical basal)
   • Medial basal (S7)
   • Anterior basal (S8)
   • Lateral basal (S9)
   • Posterior basal (S10)

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Left Lung

The left lung has two lobes (upper and lower) and 8–10 bronchopulmonary segments (variation is common). Some segments may combine due to anatomical differences.

1. Upper Lobe (4-5 segments, includes the lingula)

   • Apicoposterior (S1+S2) (fused in many cases)
   • Anterior (S3)
   • Superior lingular (S4)
   • Inferior lingular (S5)

2. Lower Lobe (4-5 segments)

   • Superior (S6)
   • Medial basal (S7) (may be absent)
   • Anterior basal (S8)
   • Lateral basal (S9)
   • Posterior basal (S10)

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Clinical Importance

1. Segmental Resection: Bronchopulmonary segments allow targeted surgical removal (e.g., for tumors or infections) without affecting other segments.
2. Localized Infections: Diseases like tuberculosis or pneumonia often localize within specific segments.
3. Aspiration Risks: Dependent segments (posterior basal in supine position) are more prone to aspiration.