Stereometric constants of the bronchial tree and arteries of the lung

Abstract

A study of five preparations of the lungs of adult dogs showed that the decrease in the mean diameters of the artery and bronchi from the roots of the lung to its periphery obeys the exponential equation D=e^−kz+b, where z is the numerical order of the branches, D the diameter of the artery or bronchus in branches of the z-th order, k the rate of change of the mean diameters, and b the logarithm of the diameter of the artery or bronchus for which z=0. The parameter b was shown to determine the dimensions of corrosion preparations whereas the parameter k is independent of the true dimensions of the lung and its mean value is 0.25. The use of the parameter k and the area beneath the intervals of branching orders 1–7, 7–14, and 14–21 of the standardized function D=e^−kz is recommended for topical diagnosis and investigation of the dynamics of lung diseases.