XIV. THE RESPIRATORY QUOTIENT OF THE BRAIN AND OF THE EXTREMITIES IN MAN

Abstract

Observations on the respiratory quotient of the brain in living unanesthetized persons have not been reported. It is possible to calculate the respiratory quotient of a portion of the body, as Doisy and Beckmann¹ pointed out, by dividing the increase in the carbon dioxide content of the venous blood by the decrease in its oxygen content, with reference to the carbon dioxide and oxygen content of arterial blood. The demonstration of Myerson, Halloran and Hirsch² that blood may be obtained safely and without undue pain from the internal jugular vein presents an opportunity for measuring the respiratory quotient of the brain in man. We are indebted to Meyerson and his associates for demonstrating the technic of making jugular punctures. The blood contained in the vein at the point of puncture, opposite the tip of the mastoid, comes from the brain. Though there are anastomoses through the cranium with