Pressure and flow waves in systemic arteries and the anatomical design of the arterial system.

Abstract

Pressure and flow waves were recorded in systemic arteries of 50 anesthetized dogs and 2 anesthetized wombats under control conditions and during occlusion of peripheral arteries. Flow was measured with electromagnetic flow-meters and pressure with Statham and Sanborn manometers. Pressure/ flow relationships were expressed as vascular impedance. The principal changes in contour and harmonic content of the waves between the heart and peripheral arteries were explained on the basis of wave reflection from 2 functionally discrete sites[long dash]1 close to the heart and representing the resultant of arterial terminations in the head, neck, and upper limbs, and the other further from the heart and representing the resultant of arterial terminations in the trunk and lower limbs. Peripheral reflection coefficients depend on the spatial dispersion of arterial terminations (and so, body shape) as well as on arteriolar tone. Differences in body shape explain in part the different pressure and flow patterns in corresponding arteries of different mammals. The concept of arterial "standing waves" was re-examined; criticism of this concept was affirmed.