(2) There are two kinds of teeth-- anterior and posterior. The anterior teeth
are also known as incisors and canine teeth. The anterior teeth serve as choppers.
They chop off mouth-size bites of food items. The posterior teeth are called molars.
They are grinders. They increase the surface area of food materials by breaking them
into smaller and smaller particles.
(3) Humans have two sets of teeth--deciduous and permanent. Initially, the
deciduous set includes 20 baby teeth.
DECIDUOUS = to be shed
These are eventually replaced by a permanent set of 32.
b. Jaws. There are two jaws--the upper and the lower. The upper is called the
maxilla. The lower is called the mandible.
(1) In each jaw, there are sockets for the teeth. These sockets are known as
alveoli. The bony parts of the jaws holding the teeth are known as alveolar ridges.
(2) The upper jaw is fixed to the base of the cranium.
The lower jaw is movable. There is a special articulation (T-MJ--temporo-mandibular
joint) with muscles to bring the upper and lower teeth together to perform their functions.
c. Palate. The palate serves as the roof of the mouth and the floor of the nasal
chamber above. Since the anterior two-thirds is bony, it is called the hard palate. The
posterior one-third is musculo-membranous and is called the soft palate. The soft
palate serves as a trap door to close off the upper respiratory passageway during
d. Lips and Cheeks. The oral cavity is closed by a fleshy structure around the
opening. Forming the opening are the lips. On the sides are the cheeks.
e. Tongue. The tongue is a muscular organ. The tongue is capable of internal
movement to shape its body. It is moved as a whole by muscles outside the tongue.
Interaction between the tongue and cheeks keeps the food between the molar teeth
during the chewing process. When the food is properly processed, the tongue also
initiates the swallowing process.
f. Salivary Glands. Digestion is a chemical process which takes place at the
wet surfaces of food materials. The chewing process has greatly increased the surface
area available. The surfaces are wetted by saliva produced by glands in the oral cavity.
Of these glands, three pairs are known as the salivary glands proper.
g. Taste Buds. Associated with the tongue and the back of the mouth are
special clumps of cells known as taste buds. These taste buds literally taste the food.
That is, they check its quality and acceptability.