The mouth (oral cavity) is an opening in the face which is the entry point for food and water in the gastrointestinal tract. It is surrounded by the lips and contains teeth and a tongue which are responsible for the mechanical breakdown of food. The process in which food is chewed is called mastication it causes a decrease in food particale size. The chewed food is then mixed with saliva containing salivary amylase thus beginning the digestion of carbohydrates as it breaks down starch and glycogen .
The mouth also houses the glottis and epiglottis which is one of the entry points for air entering the respiatory tract .