Gomes Rute F M, Bates Jason H T
Meakins-Christie Laboratories, McGill University, 3626 St. Urbain Street, Montreal, Que, H2X 2P2, Canada.
Respir Physiol Neurobiol. 2002 Jun;130(3):317-25. doi: 10.1016/s0034-5687(02)00017-8.
The flow resistance of the pulmonary airway tree (Raw) is disproportionately larger in large animals than in smaller ones. This is thought to be due to the fact that smaller animals have relatively wider central airways than larger animals. However, Raw is not determined solely by the diameter of the main bronchi or trachea. It depends on the dimensions of all the individual airways and how they are connected. We investigated how the degree of asymmetry of the airway tree, the number of airway orders, and dimensions of the individual airways combine to determine Raw. We performed this investigation using computer models of the airway trees of two different sized isomorphic rodents that differ in weight by more than two orders of magnitude-the harvest mouse and the giant pouched rat. We calculated airway resistance in these models under various conditions, and confirmed that the smaller species has a lower Raw relative to body size than the larger species. We also showed that these differences are due to a combination of differences both in relative airway diameters and in the degree of asymmetry of the airway trees.
大型动物的肺气道树气流阻力（Raw）比小型动物大得多。这被认为是由于小型动物的中央气道相对比大型动物更宽。然而，Raw并非仅由主支气管或气管的直径决定。它取决于所有单个气道的尺寸以及它们的连接方式。我们研究了气道树的不对称程度、气道分支级数和单个气道尺寸如何共同决定Raw。我们使用两种不同大小的同构啮齿动物（体重相差两个以上数量级——收获鼠和巨囊鼠）的气道树计算机模型进行了这项研究。我们在各种条件下计算了这些模型中的气道阻力，并证实相对于体型，较小的物种比较大的物种具有更低的Raw。我们还表明，这些差异是由于相对气道直径和气道树不对称程度的差异共同造成的。
