Reflex mechanisms and the central nervous system

Abstract

The cardiovascular system in the resting body normally operates under tonic restraint, reflexly engendered from sensory endings situated in the systemic arterial walls, in the walls of the cardiac chambers and the great veins. The nature of this reflex restraint has been most fully documented by experiments which make use of the accessibility of the carotid sinus, the anatomy of which permits its vascular isolation and perfusion. The characteristics of the reflex cardiovascular responses obtained by altering local conditions in the innervated carotid sinus are qualitatively similar to those which may be obtained (with more difficulty) by selective alteration of the local circumstances in the other systemic arterial mechanoreceptor areas, viz: the aortic arch, the root of the right subclavian artery, and in parts of the common carotid artery itself. Correspondingly the effects of altering conditions in the carotid bifurcation detailed below can be taken as approximately representative of the systemic arterial mechanoreceptor reflexes as a whole.