[Upper airway: innervation and chemical regulation of respiration]

The general physiology of respiratory function of upper airway muscles is presented. Comparative aspects of upper airway structure and of breathing mechanism are discussed briefly. Contribution of upper airway inspiratory muscle activity and roles of muscle activity during post inspiratory phase are described. The activity of upper airway muscles or innervating cranial nerve motoneurons and their alteration by chemical stimuli are greatly modified by vagal pulmonary afferents. Functional significance of these changes during upper airway obstruction are discussed.