THE MECHANISM OF THE RESPIRATORY WAVES IN SYSTEMIC ARTERIAL BLOOD PRESSURE

Abstract

Experimental evidence is produced to show that pulmonary resistance is diminished and vascular capacity increased during inflation of the lungs; on deflation pulmonary resistance is increased and vascular capacity diminished. The opposite conditions hold in lungs inflated by positive pressure. By an improved method it is shown that in man the respiratory waves in systemic arterial blood pressure consist of an immediate fall on inspiration, and immediate rise on expiration. These facts are adequately explained on the basis of passive changes occurring in the capacity of the vascular bed of the lungs during the respiratory phases.