Physiology and pathophysiology of glottic reflexes and pulmonary aspiration: from neonates to adults

Pulmonary aspiration is the consequence of abnormal entry of fluid, particulate material, or endogenous secretions into the airway. The two main types of aspiration scenarios include anterograde aspiration, which occurs during swallowing, and retrograde aspiration, which can occur during gastroesophageal reflux (GER) events. The important structures that protect against aspiration include the aerodigestive apparatus: pharynx, upper esophageal sphincter, esophageal body, glottis and vocal cords, and airway. In this article we review the neuroanatomy, physiology, and pathophysiology pertinent to glottic reflexes and airway aspiration across the age spectrum from neonates to adults. We also discuss recent advances in our understanding of glottal reflexes and the relationship of these reflexes to developmental anatomy and physiology, the pathophysiology of aspiration, and aerodigestive interactions.