Bronchopulmonary Segments: Surgical Anatomy

1. Definition

A bronchopulmonary segment is a portion of the lung supplied by a specific tertiary (segmental) bronchus and an accompanying branch of the pulmonary artery. It is the smallest functionally independent unit of the lung.

2. Right Lung (10 Segments)

• Upper Lobe: Apical, Posterior, Anterior.
• Middle Lobe: Lateral, Medial.
• Lower Lobe: Superior, Medial Basal, Anterior Basal, Lateral Basal, Posterior Basal.

3. Left Lung (8-10 Segments)

• Upper Lobe: Apico-posterior, Anterior, Superior lingular, Inferior lingular.
• Lower Lobe: Superior, Anteromedial basal, Lateral basal, Posterior basal.

4. Clinical Importance

• Segmentectomy: Since each segment has its own vascular and air supply, surgeons can remove a single diseased segment without damaging surrounding healthy tissue.
• Aspiration Pneumonia: Commonly affects the superior segment of the lower lobe when a patient is in the supine position.

5. Questions

1. How many segments are typically in the right middle lobe?
2. Which segment is most prone to aspiration in a bedridden patient?
3. What is the difference between a lobe and a segment?