THE EFFECT OF VARIATION IN POSTURE ON THE OUTPUT OF THE HUMAN HEART

Abstract

The circulatory minute volumes of a series of normal men and women were determined in the recumbent, sitting and erect postures by Marshall and the author''s method. Contrary to previous findings, the results showed that the circulatory minute volume is maintained constant despite variations in posture. The effect of posture on the respiratory mechanisms is pointed out, and it is shown that homogeneous mixture in a lung-bag system is less easily obtained in the recumbent than in the standing posture. The physiological implications involved in the conception of a constancy in the circulatory minute volume with varying posture are discussed.