Autonomic nervous reflexes in respiration elicited by mechanical stimulation of the velopharyngeal region in rabbits.

Reflex increases in peak activity of the diaphragm and expiratory pharyngeal muscles were recorded in lightly anesthetized and vagotomized rabbits by gentle mechanical stimulation of the nasal surface of the soft palate and of the posterior wall of the nasopharynx. No noticeable change in diaphragmatic activity was evoked by gentle mechanical stimulation of the oral surface of the soft palate and of the posterior wall of the oropharynx. The present results suggest that afferent signals from mechanoreceptors of the velopharyngeal region may contribute to reflex augmentation of respiration.