Effect of various sensory stimuli on reflex laryngeal adduction.

Various types of sensory stimuli may influence reflex laryngeal adduction. The reccurrent laryngeal nerve responses evoked by single shock and repetitive electrical stimulation of a number of sensory nerves have been neurophysiologically observed in twenty-five adult cats. Stimulation of major cranial afferents produces strong adductor responses. The magnitude of these evoked responses is approached only by stimulation of the splanchnic nerve in the abdomen. On the other hand, comparable stimulation of special sensory and spinal somatic sensory nerves produces rapidly attenuated evoked adductor responses. We postulate that while these latter adductor responses may be insuffcient to produce strong glottic closure, they may effectively modify phonatory function of the larynx. We have, therefore, attempted to demonstrate the effects of various sensory elicitations upon reflex laryngeal adduction as they may compositely influence both protective and phonatory control of this organ system.