Mouth

From ArticleWorld

The mouth is the cavity where food is initially inserted and where it is made more malleable for swallowing. Saliva, made by the salivary gland, begins to digest the food before it reaches the stomach. The mouth also carries an important function in the formation of clearly articulated speech. Taste and tactile sense are the primary sensory functions of the mouth.

Anatomy

The mouth is also called the buccal or oral cavity. In nearly every non-microscopic animal species it is located at the head. In humans, the opening of the mouth is marked by the lips which help hold food in during chewing and which participate in speech articulation.

Inside the mouth, the roof of the mouth is the palate and the floor of the mouth is dominated by the tongue. The tongue actually fixed to bony structures deep beneath the mouth. Salivary ducts open out into the mucus membranes of the mouth, which provide saliva for keeping the mouth moist and for helping with the act of chewing. The roof of the mouth consists of the palate. The back of the mouth opens out into the pharynx. Besides the tongue, the mouth contains teeth that, together with saliva and the tongue, prepare the food into moist, malleable boluses which can then be swallowed.

Function

The mouth participates in several different functions. As a receptacle for food, the mouth takes in chunks of food that are generally not appropriate for immediate swallowing. Using the tongue to push food around and to smash it against the palate, the food is directed toward the teeth to be broken down into smaller moist chunks. Saliva, which contains digestive enzymes, is stimulated in the presence of food.

The mouth is also used for the production of speech. When air is passed through it from the lungs, speech sounds are generated by different positions of the lips and the tongue. The pushing of the tongue against the front teeth is also necessary to clearly articulate speech.

Taste sensation occurs inside the mouth and is augmented by the nose. The upper surface of the tongue is coated with multiple papillae (or projections) that give the tongue its rough surface. The papillae carry taste buds on them that can identify any of four different taste categories. These categories are the sensations of sweet, bitter, salty and savory. The true distinction of taste, however, depends on the combined functions of the tongue and the olfactory bulb in the nose.