Conclusion

Abstract

In these pages we have analysed the design and dimensions of typical pulmonary structures which appeared to be of primary functional significance in ensuring adequate conditions for gas exchange between air and blood in the lung. These studies have yielded two major results. Firstly, it became apparent that the human lung must be constructed according to a weIl specified plan: The airway system was found to branch over the same average number of generations, and the number of structural elements, such as alveoli or capillaries, was shown to be essentially identical for aIllungs investigated, regardless of the size of the organ. Secondly, it has been possible to formulate fundamental dimensional relations between various structural parameters and the lung size, which led to the establishment of geometrical and dimensional models of the human lung.