Oxygen transport by blood in relation to body size.

Abstract

AN understanding of the mechanisms of oxygen transport in mammals requires a knowledge of the rate of oxygen consumption (which represents the quantity of oxygen transported), the arteriovenous oxygen concentration difference (which expresses the amount of oxygen delivered per unit of circulatory load), and the oxygen tension in mixed venous blood (which expresses the “activity” of oxygen in capillary blood). These factors have previously been compared in resting, unanaesthetized sheep and humans and a striking similarity of all three measurements was noted despite great species differences in blood haemoglobin concentration and oxygen affinity1.