Postnatal enlargement of human tracheobronchial airways and implications for particle deposition
Version of Record online: 27 JAN 2005
Copyright © 1985 Wiley-Liss, Inc.
The Anatomical Record
Volume 212, Issue 4, pages 368–380, August 1985
How to Cite
Phalen, R. F., Oldham, M. J., Beaucage, C. B., Crocker, T. T. and Mortensen, J. (1985), Postnatal enlargement of human tracheobronchial airways and implications for particle deposition. Anat. Rec., 212: 368–380. doi: 10.1002/ar.1092120408
- Issue online: 27 JAN 2005
- Version of Record online: 27 JAN 2005
- Manuscript Accepted: 14 MAR 1985
- Manuscript Received: 18 OCT 1984
In support of predictions for inhaled particle deposition, morphometric measurements were taken on 20 replica airway casts of people aged 11 days to 21 years. Measurements of right upper lobe airway lengths, diameters, and branching angles were made such that a growth model suitable as input to predictive equations for particle deposition efficiency was obtained. The tracheobronchial airways growth was describable by linear regressions on body length. The length-to-diameter ratio of growing airways did not change in any simple way as a function of airway generation. Airflow rates for a given state of physical activity for various ages were found from previously published data to be describable by linear regressions on body mass. Three states of physical exertion–low activity, light exertion, and heavy exertion–were used for modeling purposes. The computed particle deposition efficiencies indicate that under most circumstances smaller (younger) people will have greater tracheobronchial deposition efficiencies than larger (older) people. For example, tracheobronchial dose on a per kilogram body mass basis for 5-μmdiameter particles may be more than 6 times higher in the resting newborn than in the resting adult assuming equivalent deposition efficiencies above the larynx.