The swallowing process begins when food or liquid is chewed and mixed with saliva in the mouth. This mixture, called a bolus, is then pushed to the back of the throat by the tongue. The pharynx muscles contract to help move the bolus down toward the esophagus, while the epiglottis closes over the windpipe to prevent choking. Once the bolus reaches the esophagus, a series of wave-like muscle contractions, known as peristalsis, propel it down to the stomach. This process is involuntary and occurs automatically, allowing for the safe passage of food and liquids without conscious effort.