palate, called the nasal cavity.
Air then passes from the nasal cavity to the nasopharynx, which is a chamber
breathing and eating passageways. This allows mammals to chew food and breathe at
the same time. Only mammals truly chew their food and have teeth specialized for
chewing. After air enters the glottis, it proceeds through the larynx and trachea to the
The roof of the oral cavity is formed by a bony palate, the hard palate. At the posterior
end of the hard palate the bone ends and the roof of the mouth becomes soft, i.e. the soft
palate. (The difference in texture is not notable on the models, but bone is modeled in the
hard palate. ) The oral cavity is that part of the digestive tract from the lips to the end of
the hard palate.
secreted in saliva, are mixed with the food during chewing. Amylase catalyzes the
breakdown of amylose, or starch, into simpler carbohydrates.
The tongue pushes food from the oral cavity into the region ventral to the soft
eventually leads to the lungs. Note the two openings in the pharynx. One goes to the
trachea, which is always open due to its rings of cartilage, and the other opening is to the
When food enters the oropharynx, a reflex makes the epiglottis fold back, closing
peristaltic contractions of the esophagus push the food to the stomach. No digestion
occurs in the esophagus. It is just a passageway that connects the pharynx to the