Expansion
Anterior chest is mostly upper lobe; posterior chest is mostly lower lobe
Expansion
- Anterior chest - predominantly upper lobes, plus the right middle lobe and the lingula low on each side
- Lateral chest (axilla) - all lobes are accessible
- Posterior chest - predominantly lower lobes
This follows from the obliquity of the fissures. The oblique fissure runs from about the T3 spinous process posteriorly to the sixth costal cartilage anteriorly, so most of the lower lobe lies behind. The horizontal fissure on the right runs from the fourth costal cartilage to meet the oblique fissure in the mid-axillary line.
The practical point for examination: a right middle lobe or lingular problem is easily missed if only the back is auscultated, and a lower lobe consolidation is easily missed if only the front is.