Mouth and Salivary Glands

Digestion begins in the mouth, where chemical and mechanical digestion occurs. Saliva or spit, produced by the salivary glands (located under the tongue and near the lower jaw), is released into the mouth. Saliva begins to break down the food, moistening it and making it easier to swallow. A digestive enzyme (called amylase) in the saliva begins to break down the carbohydrates (starches and sugars). One of the most important functions of the mouth is chewing. Chewing allows food to be mashed into a soft mass that is easier to swallow and digest later.

Movements by the tongue and the mouth push the food to the back of the throat for it to be swallowed. A flexible flap called the epiglottis closes over the trachea (windpipe) to ensure that food enters the esophagus and not the windpipe to prevent choking.