Meeting Abstract

9.7  Jan. 4  The Ontogeny of Epiglottal Movement during Swallowing in Mammals GERMAN, R.Z.*; CROMPTON, A.W.; THEXTON, A.J.; Johns Hopkins University; Harvard University; King’s College, London rz.german@jhmi.edu

In mammalian feeding, the path that food takes crosses the airway. The function of the epiglottis, the superior cartilage of the larynx, during swallowing is debated and developmental changes in its function unknown. To test the role this structure plays during the pharyngeal swallow, we placed radio opaque markers in the palatopharyngeal arch, tip of the epiglottis and bases of the thyroid and basihyoid cartilages in infant pigs. We measured the passage of liquid from the valleculae to the esophagus in lateral and dorso-ventral views by videofluroscopy. Prior to a swallow, the dorsal rim of the larynx was firmly held within the sphincter formed by the palatopharyngeal arch, maintaining a patent airway. During a swallow in the youngest animals, liquids reached the esophagus via the piriform recesses by moving around the stationary epiglottis. As animals matured, but still prior to weaning, the epiglottal tip moved rapidly backwards during a swallow, even though the milk continued to travel lateral to the laryngeal opening. In such swallows the palatopharyngeal sphincter closed and the tip of the epiglottis moved backwards protecting the airway opening. Within a few days epiglottal flipping became increasingly regular, until about the time of weaning, when flipping occurred consistently, and milk always traveled over the epiglottis during a swallow. The movement of the epiglottis during swallowing matures prior to the start of the consumption of solid food, and is implicated in the functional separation of the food pathway and airway.