AJP - Regulatory, Integrative and Comparative Physiology, Vol 249, Issue 3 335-R340, Copyright © 1985 by American Physiological Society
Propagation of pressure pulse in kangaroo arterial system
A. P. Avolio, W. W. Nichols and M. F. O'Rourke
The pressure pulse contour in the ascending aorta of kangaroos is markedly
different from that seen in other species, but the changes undergone by the
pulse propagating along the aorta are quite similar. Alteration of wave
contour and progressive amplification of the pulse in the distal aorta and
peripheral arteries of other mammals have been attributed to elastic
nonuniformity of the aorta and to peripheral wave reflection. In kangaroos
the aorta approximates a uniform tube with essentially constant
viscoelastic properties, whereas wave reflection from the lower body
appears to be unusually intense and to emanate from a single functionally
discrete reflecting site; this appears to be the result of arterial
terminations in the muscular lower body. Intense wave reflection from the
lower body is the dominant mechanism responsible for changes in the
pressure pulse of kangaroos between the ascending aorta and peripheral
arteries. Contour of the pulse in the ascending aorta is attributable to
this and to close proximity of reflecting sites in the upper body.
