These three stages are controlled by nerves that connect the digestive tract to the brain. The tongue pushes food and liquids to the back of the mouth towards the throat. A flap called the epiglottis closes off the passage to the windpipe so food cannot get into the lungs. The muscles in the throat relax. The epiglottis opens again so we can breathe.
Liquids fall through the esophagus into the stomach by gravity.
Muscles in the esophagus push food toward the stomach in wave-like movements known as peristalsis. Swallowing disorders occur when one or more of these stages fails to take place properly. Dysphagia can result in aspiration which occurs when food or liquids go into the windpipe and lungs. Children with dysphagia usually have trouble eating enough, leading to inadequate nutrition and failure to gain weight or grow properly. The symptoms that children with dysphagia have may be obvious, or they can be difficult to associate with swallowing trouble.