Anatomy, pathology, and physiology of the tracheobronchial tree: Emphasis on the distal airways  Dallas M. Hyde, PhD, Qutayba Hamid, MD, PhD, Charles G. Irvin, PhD  Journal of Allergy and Clinical Immunology  Volume 124, Issue 6, Pages S72-S77 (December 2009) DOI: 10.1016/j.jaci.2009.08.048 Copyright © 2009 American Academy of Allergy, Asthma & Immunology Terms and Conditions

Fig 1 Histologic comparison of the airspace walls in the same airway generations (A and D are from tracheas, B and E are from proximal bronchi, and C and F are from bronchioles) of an adult male rhesus monkey (Fig 1, A–C) and an adult male Swiss Webster mouse (Fig 1, D–F). The luminal airspace (top) and the epithelium are set so that the basal lamina matches for both species. The epithelium is more complex and taller in the proximal airways of monkeys than at the same site in mice. Smooth muscle occupies a larger portion of the interstitium in monkeys than in mice at all airway levels. All micrographs are at the same magnification, with the magnification bar indicating 10 μm. Toluidine blue staining was used. Journal of Allergy and Clinical Immunology 2009 124, S72-S77DOI: (10.1016/j.jaci.2009.08.048) Copyright © 2009 American Academy of Allergy, Asthma & Immunology Terms and Conditions

Fig 2 Function of the tracheobronchial tree is reflected by the physiologic lung function measures as indicated. Freq R, Resistance at low or high frequencies; RL, lung resistance; Rp, peripheral resistance; Sgaw, specific airway conductance. Journal of Allergy and Clinical Immunology 2009 124, S72-S77DOI: (10.1016/j.jaci.2009.08.048) Copyright © 2009 American Academy of Allergy, Asthma & Immunology Terms and Conditions