The Digestive System - Mouth 1. Explain four functions of the oral cavity. 2. Components: lips, cheeks, palate, uvula, tonsils, fauces a. The separates the mouth from the nasal passages. 3. Saliva is mainly composed of Circle the term that does not belong in each of the following groupings. tongue parotid sublingual submandibular salivary glands analysis excretion mechanical processing lubrication begin digestion.