This increased stiffness has been suggested to be related to the structure
of the arterial wall. This implies that the compliance-pressure relation is
not a constant one. The declining arterial compliance with increasing
pressure has been observed in the central aorta and in individual arteries.
The inverse exponential relation between compliance and pressure for
the arterial system is shown in Fig. 4.5.8.
Compliance plotted against mean arterial blood pressure reflecting the
The relationship is nonlinear, implying that at higher
distending pressures the intraluminal volume change is smaller, resulting in a lower
compliance. The decrease in arterial compliance with increasing blood pressure follows a
negative exponential function.
nonlinear model of the arterial system incorporating a pressure-
dependent compliance element
is shown in Fig. 4.5.9 (Li et al.,
The model consists of the characteristic impedance of the
the peripheral resistance
compliance is exponentially related to pressure and is expressed as