The Seventh Heymans Memorial Lecture Ghent, February 18, 1995. Physiological aspects of small arteries.

This review provides a brief overview of some of the structural and functional properties of small arteries, and of the factors which determine these. First, the evidence is reviewed concerning the importance of small arteries in the control of peripheral resistance. Then, receptor-mediated and myogenic excitation-contraction coupling mechanisms are discussed, in particular as regards the crucial role of membrane potential in these vessels. Finally, the characteristics of small arteries in hypertension are reviewed, with special attention to the structural abnormalities and their possible participation in the pathogenesis of the disease. The structural abnormalities of small arteries in hypertension are likely responsible for the reduced vascular reserve in this disease and consequent morbidity. It is suggested, however, that the small arteries are not in themselves determinants of blood pressure, rather they act as effector organs of the cardiovascular system. The further understanding of the physiology and pathophysiology of small arteries thus remains an important goal as regards the elucidation of the function of the cardiovascular system in health and disease.