The first stages of digestion occur when a person smells and sees food, triggering the salivary glands to produce the saliva that will break down food once it is eaten.
The Digestive System
Next, the mouth breaks up food by chewing it up with its teeth. The tongue mixes saliva into the smaller bits of food to break it down further and move it to the throat.
After that, the muscular esophagus, which is located in the throat, uses peristalsis to push the chyme into the stomach.