Abstract
Swallowing is known to be one of the most complex reflexes in the body. It takes within a second for the food bolus to be propelled from the oral cavity through the oropharynx to the esophagus. The complexity may be partially caused by the fact that it can be evoked not only reflexively, but also voluntarily under the higher center control. In the past, it was believed that the swallowing event was critically divided into three, i.e., oral, pharyngeal and esophageal stages depending on where the bolus flew. Recently, Dr. Palmer and his colleagues showed that food passed into the oropharynx before swallowing during natural mastication. A videofluorographic study of feeding in humans showed that triturated food was routinely transported through the pillars of the fauces and the bolus was formed on the posterior surface of the tongue. What still remains unclear is the mechanism that coordinates the chewing and swallowing movements to complete the deglutition and that prevents aspiration of the forming oropharyngeal bolus. On the other hand, the swallowing can be modulated by the sensory feedback, such as the consistency or volume of the bolus, to handle the food bolus. In this symposium, kinematographic and electromyographic evaluation of swallowing function in humans and animals will be discussed. [J Physiol Sci. 2007;57 Suppl:S13]
