|
|
||||||||
AJP - Regulatory, Integrative and Comparative Physiology, Vol 245, Issue 6 831-R836, Copyright © 1983 by American Physiological Society
ARTICLES |
A. P. Avolio, M. F. O'Rourke and M. E. Webster
Pulse-wave velocity (PWV) and pulse-wave amplification (PWA) were measured over a proximal [51 +/- 3 (SE) cm] and distal segment (60 +/- 6 cm) of the common descending aorta of 10 anesthetized diamond python snakes (Morelia spilotes). For proximal and distal segments, PWV values were 551 +/- 66 and 921 +/- 116 cm/s and PWA were 0.91 +/- 0.05 and 0.91 +/- 0.06, respectively. PWV for proximal and distal segments were significantly different (P less than 0.02), but PWA were not. PWA for separate harmonics of heart frequency showed no significant increase above unity. Increase of PWV between distal and proximal aorta indicates a reduction in arterial distensibility, a phenomenon that in other species is associated with amplification of the pressure pulse; this was not observed in snakes. Using a simple elastic tube model 56 cm in length and 3 mm in diameter it was found that the amplification produced by the measured PWV changes is offset by attenuation due to viscous damping. Thus similarity of pulse-wave contour throughout the snake's aorta is attributable to the opposing effects of elastic nonuniformity and viscous damping.
This article has been cited by other articles:
![]() |
D. A. Syme, A. K. Gamperl, M. H. Braun, and D. R. Jones Wave reflection effects in the central circulation of American alligators (Alligator mississippiensis): what the heart sees Am J Physiol Heart Circ Physiol, October 1, 2006; 291(4): H1670 - H1678. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |