ON THE REFLEX REGULATION OF RESPIRATION FROM THE CAROTID SINUS

¹ The Department of Physiology, University College, London

Bilateral denervation of the carotid sinus, in the dog, was followed by alterations in the character of respiration, the latter becoming, as a rule, less deep, and its rhythm being often accelerated.

The effect upon the magnitude of the pulmonary ventilation per unit of time was variable.

A decrease of the pulmonary ventilation was obtained whenever the inhibitory effect of the endosinual pressure upon respiration was weak, i.e. when occlusion of the carotids caused little or no augmentation of breathing.

The depressing effect upon the respiratory movements of denervating the carotid sinus, when evident, seemed more marked during respiration in air than when the animal was breathing a mixture of carbon dioxide (3 to 5 per cent.) and air.

The expenses of this research were defrayed by a grant from the Foulerton Reserve Fund of the Royal Society, for which I wish to express my sincere thanks and deep gratitude.

I am also very grateful to Professor C. Lovatt Evans for his interest in this work, and for his valuable criticism, and to Mr. E. G. White for his kind assistance in some of the experiments.