The high-pressure systemic arterial network plays a major physiological role as it buffers the impact of the blood flow wave generated by the left ventricle and transforms it into a more continuous flow in the peripheral arterioles. In ageing processes unrelated to hypertensive or vascular disease the structural properties of the arterial network are significantly altered. The collagen, elastin and smooth muscle contents of the tunica media and the geometrical arrangement of arterial wall components are constantly modified according to the subject's age. These morphometric changes are responsible for changes in the mechanical properties of the arterial walls leading to rigidity. An increase in caliber of the arterial lumen has been found in all studies; it partially compensates for the effects of arterial wall rigidity on vascular compliance, thereby limiting the haemodynamic and functional changes that occur in blood circulation.