AFFERENT IMPULSES AS A CAUSE OF INCREASED VENTILATION DURING MUSCULAR EXERCISE

Abstract

In human subjects active movements of the extremities caused increased ventilation. The result was not affected by the presence of an inflated blood pressure cuff proximal to the moving parts of the extremity. Passive movements likewise increased the breathing of both man and dog. Cutting the spinal cord of dogs abolished the effect. When the posterior extremity of a dog was severed from the body except for the femoral artery and vein and the sciatic nerve, movements of the extremity caused increase in ventilation regardless of obstruction of the blood vessels. Movements of the extremity were not associated with increase in ventilation if the sciatic nerve had been divided. Hence the authors conclude that the increase in ventilation during muscular exercise, not severe enough to cause detectable alteration in the oxygena-tion or the acid-base condition of the blood, is due[long dash]in part at least.