|
|
||||||||
Journal of Applied Physiology, Vol 77, Issue 2 660-670, Copyright © 1994 by American Physiological Society
ARTICLES |
G. S. Krenz, J. Lin, C. A. Dawson and J. H. Linehan
Biomedical Engineering Department, Marquette University, Milwaukee 53233.
Model arterial trees were constructed following rules consistent with morphometric data, Nj = (Dj/Da)-beta 1 and Lj = La(Dj/Da)beta 2, where Nj, Dj, and Lj are number, diameter, and length, respectively, of vessels in the jth level; Da and La are diameter and length, respectively, of the inlet artery, and -beta 1 and beta 2 are power law slopes relating vessel number and length, respectively, to vessel diameter. Simulated heterogeneous trees approximating these rules were constructed by assigning vessel diameters Dm = Da[2/(m + 1)]1/beta 1, such that m-1 vessels were larger than Dm (vessel length proportional to diameter). Vessels were connected, forming random bifurcating trees. Longitudinal intravascular pressure [P(Qcum)] with respect to cumulative vascular volume [Qcum] was computed for Poiseuille flow. Strahler-ordered tree morphometry yielded estimates of La, Da, beta 1, beta 2, and mean number ratio (B); B is defined by Nk + 1 = Bk, where k is total number of Strahler orders minus Strahler order number. The parameters were used in P(Qcum) = Pa [formula: see text] and the resulting P(Qcum) relationship was compared with that of the simulated tree, where Pa is total arterial pressure drop, Q is flow rate, Ra = (128 microLa)/(pi D4a (where mu is blood viscosity), and Qa (volume of inlet artery) = 1/4D2a pi La. Results indicate that the equation, originally developed for homogeneous trees (J. Appl. Physiol. 72: 2225-2237, 1992), provides a good approximation to the heterogeneous tree P(Qcum).
This article has been cited by other articles:
![]() |
K. L. Karau, G. S. Krenz, and C. A. Dawson Branching exponent heterogeneity and wall shear stress distribution in vascular trees Am J Physiol Heart Circ Physiol, March 1, 2001; 280(3): H1256 - H1263. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. A. Dawson, G. S. Krenz, K. L. Karau, S. T. Haworth, C. C. Hanger, and J. H. Linehan Structure-function relationships in the pulmonary arterial tree J Appl Physiol, February 1, 1999; 86(2): 569 - 583. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. C. Parker, C. B. Cave, J. L. Ardell, C. R. Hamm, and S. G. Williams Vascular tree structure affects lung blood flow heterogeneity simulated in three dimensions J Appl Physiol, October 1, 1997; 83(4): 1370 - 1382. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |