Newer concepts of anatomy of the lungs; advantages to surgeons, internists, bronchoscopist and radiologists.

In the newer concept of the anatomical divisions of the lungs, the bronchopulmonary segment is the primary unit. Specific lung areas are identified by their relationship to the branch of the bronchus that serves them. The left upper lobe apical segment, for example, is that which is supplied by the left upper lobe apical bronchus. The boundaries of the segments are definitive; thin tissue surrounds each segment. Some diseases of the lungs tend to progress only "through channels"-reaching a segment via the specific airway serving it, and then frequently remaining within the segmental boundaries. The concept is of particular importance to surgeons because of the trend toward segmental resection and salvage of vital lung tissue. In addition, a more definitive nomenclature, useful to surgeons, internists, radiologists and bronchoscopists in designating the location of a lesion or a foreign body, is possible.