In human beings, digestion of food starts from the mouth. Mouth opens into a chamber or cavity called buccal cavity. The buccal cavity contains teeth, tongue and salivary glands. The teeth cut the food into small pieces, chew and grind it. Thus, teeth help in physical digestion. Salivary glands produce saliva which mixes with the food. Saliva is a watery fluid that makes the food slippery for swallowing. These glands help in chemical digestion of food.

The saliva contains an enzyme called salivary amylase which digests the starch into maltose sugar.