EFFECT ON RESPIRATION, BLOOD PRESSURE AND CAROTID PULSE OF VARIOUS INHALED AND INSUFFLATED VAPORS WHEN STIMULATING ONE CRANIAL NERVE AND VARIOUS COMBINATIONS OF CRANIAL NERVES

Abstract

The chief change in respiration from olfactory stimulation by inhalants is depression and slowing. A sneeze is evoked only in unanesthetized or partially anesthetized animals. Trigeminal stimulation by inhalants produces inhibition and often a sneeze. Inhalation stimulation of either the trigeminal or olfactory nerve results in a rise in blood pressure and usually a slowing and strengthening of the carotid pulse. The venous pressure in the superior vena cava exhibits a similar rise and slowing of the atrial pulse, but discloses a marked weakening of the atrial beat. The effect of a number of agreeable, disagreeable and irritating inhalants on respiration and circulation is reported. It was shown that the respiratory and ciroulatory changes in respiration and circulation during inhalation were not due to humoral-peripheral and humoral-medulla stimulation resulting from absorption of these vapors or to mechanical vagus stimulation or cessation of stimulation.