REGULATION OF PULMONARY ARTERIAL BLOOD PRESSURE

Abstract

SINCE Hering's discovery,¹ about twenty years ago, that increased pressure in the carotid sinus reflexly produces bradycardia and arteral hypotension, a great deal of work has been done in the regulation of systemic arterial blood pressure. It has been proved, especially by the work of Heymans and his associates,^1a that the sinus and aortic regions are of paramount importance in this connection; on the one hand, increased arterial pressure stimulates pressosensitive endings of the sinus and aortic nerves and provokes inhibition of the cardiac and vasomotor centers, and, on the other hand, the lowering of the oxygen and the rise of the carbon dioxide tension in the arterial blood stimulate chemoreceptors and from them, by way of a reflex, also the centers mentioned. Having been for some time engaged in studies on these questions it appeared to my colleague, Professor von Euler, and me² that it