What is the name of the upper portion of the lung?

The upper portion of the lung is referred to as the apex. This part of the lung extends above the level of the first rib and is positioned near the clavicle. Understanding the anatomy of the lungs is crucial in radiography, as imaging techniques often focus on different regions for diagnostic purposes.

The base, in contrast, is the lower part of the lung that sits on the diaphragm. The costophrenic angle refers to the angle formed between the diaphragm and the rib cage, often assessed for fluid levels in the pleural space. The hilum is the area where the bronchi, blood vessels, and nerves enter and exit the lung but does not denote the upper section itself. Thus, the apex is the correct term to describe the uppermost part of the lung.