Vascular Mechanisms Pertaining to the Intrinsic Regulation of the Cerebral Circulation

Abstract

A review is given of recent work on the vascular mechanisms that participate in the intrinsic control of the cerebral circulation. The main emphasis is given to studies carried out at the Department of Pathophysiology, Institute of Physiology of the Georgian Academy of Sciences in Tbilisi (USSR). Physiologic as well as pathophysiologic mechanisms are considered. Emphasis is given to the important role of the large arteries carrying blood to the brain—the internal carotid and the vertebral arteries (major arteries of the brain)—in the regulation of cerebral circulation. These vessels differ in several respects from the smaller cerebral (pial) arteries in their functional and vasomotor behavior. The pial arteries have mainly a "nutritive" role as demonstrated during, for example, changing demands of blood supply for the cerebral tissue. Some recent data are presented that stress the important role played by the vasomotor innervation and by humoral factors for different parts of the cerebral vascular system during normal and pathologic events. A survey is also given of mechanisms pertaining to the cerebral venous system in the various compensatory vascular reactions during pathologic states of the brain.