Swallowing is an essential life function. We swallow saliva approximately once per minute during the day and we continue to swallow as we sleep, albeit far less frequently. Nutrition and hydration are also important reasons why we swallow. One goal of swallowing is to efficiently move food and liquid into the stomach. To do this, we first coordinate several parts of the oral cavity (tongue, lips, hard and soft palates, jaw, cheeks) to break food down and then to propel food and liquid into the throat. Muscles of the throat (pharynx) continue to push food into the esophagus before it reaches the stomach. These functions can help to keep food from sticking in the throat, which could lead to choking (severe difficulty breathing because of food obstruction). Another goal of swallowing is to prevent food or liquid from entering certain parts of the respiratory tract including the larynx (voice box), trachea (wind pipe) and lungs. This is an intricate process that requires the larynx to close as food or liquid passes behind it. In addition to these movements, sensation is critical for keeping track of the position of food, liquid, and each part of the oral cavity and throat. Although complex, these events occur accurately and quickly while in multiple bodily positions, often with little thought. Swallowing naturally changes between birth and older adulthood and can remain functional throughout life.