THE CONTINUOUS MEASUREMENT OF THE VELOCITY OF VENOUS BLOOD FLOW IN THE ARM DURING EXERCISE AND CHANGE OF POSTURE

Abstract

Gibbs'' hollow needle containing a thermo-electric blood flow recorder was used, or, in certain cases of superficial (visible) vessels, a solid needle in which hot and cold thermo-junctions had been incorporated. Observations on normal human subjects showed that the velocity of blood flow in the superficial and deep veins of the arm behaves antagonistically with exercise of that arm, the flow of the deeper veins becoming more rapid and in the superficial veins slower than at rest. With moderately severe exercise involving chiefly the lower extremities (pedalling on a stationary bicycle), there is no change in the velocity of blood flow in the veins of the arms. In the superficial and deep veins, the velocity of blood flow is slower with the arm held erect, and more rapid with it hanging down, than held horizontal.