The lung apex (plural: apices) is the largest portion of the human lung, according to AnatomyExpert. It is located in the upper part of the lung, notes Wikipedia. It reaches into the bottom of the neck above the highest rib, above the other lobes of the lung.
The apices of the lungs help in filtering air. The two lungs in mammals are on each side of the heart near the backbone, notes Wikipedia. The main function of the lungs is moving oxygen from the air and through the bloodstream. The lungs also expel carbon dioxide taken from the bloodstream. Air reaches the lungs through the nose or mouth and through the windpipe.