Contemporary measurement techniques permit rite non-invasive observation of
several cardiovascular functions, both from the central and peripheral poi
nts of view. We shoe that, within? one cycle of blood through the cardiovas
cular system, the same dynamics characterizes heart function as well as blo
od flow in the capillary ben where cells exchange energy and matter. Analys
es of several quite different signals derived from respiration, cardiac fun
ction and blood flow, all reveal the existence of five almost periodic freq
uency components. This result is interpreted us evidence that cardiovascula
r dynamics is governed by five coupled oscillators. The couplings provide c
o-ordination among the physiological processes involved, and are essential
for efficiency cardiovascular function. Understanding the dynamics of a sys
tem of five coupled oscillators not only. represents a theoretical challeng
e, bit also carries practical implications for, diagnosis and for predictin
g the future behaviour of this life giving system.