Katz I, Zamel N, Slutsky A S, Rebuck A S, Hoffstein V
Department of Medicine, St. Michael's Hospital, University of Toronto, Ontario, Canada.
J Appl Physiol (1985). 1988 Dec;65(6):2390-4. doi: 10.1152/jappl.1988.65.6.2390.
We evaluated the mechanical properties of the airways sequentially from the glottis toward the main bronchi in 10 normal subjects. Plots of airway cross-sectional area vs. lung volume, measured during inspiration and expiration, were used to determine the relative magnitude of the airways vs. parenchymal hysteresis. Airway cross-sectional area was measured by means of the acoustic reflection technique. We found that the hysteresis of the proximal part of the trachea was greater than that of the lung parenchyma, whereas the hysteresis of the distal trachea and subcarinal segments of the airways was smaller than that of the lung parenchyma. The transition zone between the proximal and the more distal airway properties occurred 8-26 cm distal to the glottis. This transition zone was reproducible in its location on repeated testing in each subject but varied among subjects. To the extent that relative hysteresis of the airways depends on bronchomotor tone, our findings suggest that the bronchomotor tone is inhomogeneous, being maximal at the proximal part of the trachea and gradually decreasing toward the more distal trachea and subcarinal airway segments.
我们在10名正常受试者中，从声门向主支气管依次评估气道的力学特性。通过测量吸气和呼气过程中的气道横截面积与肺容积，来确定气道与实质组织滞后现象的相对大小。气道横截面积采用声反射技术进行测量。我们发现，气管近端的滞后现象大于肺实质，而气管远端和气道隆突下节段的滞后现象小于肺实质。气道近端和远端特性之间的过渡区出现在声门远端8 - 26厘米处。该过渡区在每个受试者重复测试时的位置具有可重复性，但在不同受试者之间有所不同。就气道的相对滞后现象取决于支气管运动张力而言，我们的研究结果表明，支气管运动张力是不均匀的，在气管近端最大，并向气管远端和气道隆突下节段逐渐降低。
