title: Relating airway diameter distributions to regular branching asymmetry in the lung.
abstract: We study the distribution Pi(n)(D) of airway diameters D as a function of generation N in asymmetric airway trees of mammalian lungs. We find that the airway bifurcations are self-similar in four species studied. Specifically, the ratios of diameters of the major and minor daughters to their parent are constants independent of N until a cutoff diameter is reached. We derive closed form expressions for Pi(N)(D) and examine the flow resistance of the tree based on an asymmetric flow division model. Our findings suggest that the observed diameter heterogeneity is consistent with an underlying regular branching asymmetry.
authors.affiliation: Center for Polymer Studies and Department of Physics, Boston University, Massachusetts 02215, USA.
authors.forename: Arnab
authors.initials: A
authors.lastname: Majumdar
authors.forename: Adriano M
authors.initials: AM
authors.lastname: Alencar
authors.forename: Sergey V
authors.initials: SV
authors.lastname: Buldyrev
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Hantos
authors.forename: Kenneth R
authors.initials: KR
authors.lastname: Lutchen
authors.forename: H Eugene
authors.initials: HE
authors.lastname: Stanley
authors.forename: Béla
authors.initials: B
authors.lastname: Suki
mesh_terms: D000818:Animals; D001703:Biophysics / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008168:Lung / Q000473:pathology*; D008953:Models, Anatomic; D008954:Models, Biological; D008956:Models, Chemical; D015233:Models, Statistical; D011652:Pulmonary Circulation; D015656:Respiratory Mechanics; D012143:Respiratory Physiological Phenomena