Which intercostal space corresponds to the lower lobe of the lungs?

• A. 6th intercostal space
• B. 2nd intercostal space
• C. 4th intercostal space
• D. 8th intercostal space

Answer: (A)

The lower lobe sits at the base of the lung along the chest wall, and its anterior border aligns with the lower portion of the rib cage. On the front of the chest, the inferior border of the lung is roughly at the 6th rib, i.e., the 6th intercostal space, near the midclavicular line. That makes the 6th intercostal space the best reference for the lower lobe in this standard anterior view.

The other spaces sit higher or lower than this reference: the 2nd and 4th interspaces correspond to regions nearer the upper and middle lobes, while the 8th interspace would be lower and more lateral/posterolateral in location. But for identifying the lower lobe’s extent on the anterior chest wall, the 6th intercostal space is the correct benchmark.