Analytical Studies of Intrapulmonary Bronchi with a Model of Irregular Dichotomy

抄録

Under some theoretical premises, irregular dichotomy was presumed on the ramification of intrapulmonary bronchial system, and mathematical derivations were discussed to give the total length of bronchial branches of radii within a certain given range. The theoretical values were assessed by counting the bronchial sections on histological slides from the lungs expanded by intrabronchial formalin infusion: from the count the total length of bronchi of the corresponding radii in a unit pulmonary volume could be estimated. The agreement of theoretical and estimated values was satisfactory in the majority of normal lungs of young and aged adults. In cases of discrepancy, the reason was sought in individual variations of the geometrical configuration of the bronchial tree, especially in different generations of bronchial branches yielding respiratory bronchioles.