Anatomy and physiology of feeding and swallowing: normal and abnormal

Eating and swallowing are complex behaviors involving volitional and reflexive activities of more than 30 nerves and muscles. They have two crucial biological features: food passage from the oral cavity to stomach and airway protection. The swallowing process is commonly divided into oral, pharyngeal, and esophageal stages according to the location of the bolus. The movement of the food in the oral cavity and to the oropharynx differs between eating solid food and drinking liquid. Dysphagia can result from a wide variety of functional or structural deficits of the oral cavity, pharynx, larynx or esophagus. The goal of dysphagia rehabilitation is to identify and treat abnormalities of feeding and swallowing while maintaining safe and efficient alimentation and hydration.