Diameters, generations, and orders of branches in the bronchial tree

K Horsfield - Journal of Applied Physiology, 1990 - journals.physiology.org
K Horsfield
Journal of Applied Physiology, 1990journals.physiology.org
Studies of bronchial tree data by West et al.(J. Appl. Physiol. 60: 1089-1097, 1986) have
shown that plots of mean diameter against generation, using log-log scales, can be
represented by a power function with harmonic modulations. Other studies have shown that
the mean diameter of the airways is exponentially related to order of branching. This paper
demonstrates that both observations are compatible with a fractal model of branching, and
because airway branching is fractal, this may explain why both are also true of the bronchial …
Studies of bronchial tree data by West et al. (J. Appl. Physiol. 60: 1089-1097, 1986) have shown that plots of mean diameter against generation, using log-log scales, can be represented by a power function with harmonic modulations. Other studies have shown that the mean diameter of the airways is exponentially related to order of branching. This paper demonstrates that both observations are compatible with a fractal model of branching, and because airway branching is fractal, this may explain why both are also true of the bronchial tree. Furthermore, the exponential relationship of mean diameter with generation in the larger airways, demonstrated by Weibel, is shown to result from the exponential relation of diameter with order in the fractal model.
American Physiological Society