AJP - Regulatory, Integrative and Comparative Physiology, Vol 240, Issue 3 200-R210, Copyright © 1981 by American Physiological Society
Functional consequences of expanded aortic bulb: a model study
K. B. Campbell, E. A. Rhode, R. H. Cox, W. C. Hunter and A. Noordergraaf
An investigation of the mechanical effects and physiological functions of
the dilated ascending aorta of diving mammals was undertaken with
mathematic modeling methods. A mathematical model of a prototype (canine)
arterial system was constructed and was evaluated by comparing
model-predicted pressure and flow wave forms at four vascular locations
with published accounts of experimental measurements. The prototype model
was modified to serve as a model of the diving mammal arterial system by
changing peripheral vascular parameters and by changing the dimensions of
the ascending aorta section of the model. This modified model gave a very
good simulation of pressure and flow behavior in diving mammal arteries
during a dive. Various distribution patterns of compliance addition to the
prototype aortic pattern were evaluated as to the effect of these patterns
on aortic input properties. It was concluded that the geometric
distribution pattern found in diving mammal arteries was optimal with
respect to reducing aortic impedance and peak systolic pressure development
and thus favored the function of the left ventricle. This mechanical
function could represent an important part of the total picture of
adaptation to prolonged ischemia.
