mouth

Orifice through which food and air enter the body. It opens to the outside at the lips and empties into the throat at the rear and is bounded by the lips, cheeks, hard and soft palates, and glottis. Its chief structures are the teeth (see tooth), tongue, and palate. It is the site of chewing and speech formation. The mouth is lined by mucous membranes containing small glands that, along with the salivary glands, keep it moist and clear of food and other debris.