The apex of the lung (Latin: apex pulmonis) is the rounded upper part of the human lung. It extends into the root of the neck, reaching between 2.5 centimetres (0.98 in) and 4 centimetres (1.6 in) above the level of the sternal end of the first rib. A sulcus, produced by the subclavian artery as it curves in front of the pleura, runs upward and lateralward immediately below the apex. It is positioned above the lobes and is partly responsible for filtering the air.
Pancoast tumor, a tumor that forms in the apex of the lung and can spread to the ribs and vertebrae