The oral cavity contains the lips, teeth, tongue, hard and soft palate, tonsils, and three pairs of salivary glands. The oral cavity is bounded by the lips and cheeks and is the first part of the digestive tract. It contains the teeth for chewing and the tongue for holding food and assisting in speech. The salivary glands produce saliva to keep the oral cavity moist and begin digestion of food.
3. ORAL CAVITY
The oral cavity, or mouth, is the first part of the digestive
tract
It is bounded by the lips and cheeks and contains the teeth
and tongue.
4. LIPS
Lips are muscular structures, formed mostly by the
orbicularis muscle.
The color from the underlying blood vessels can be
seen through the thin, transparent epithelium, giving
the lips a reddish-pink appearance.
5. TONGUE
Is a large, muscular organ
that occupies most of the
oral cavity.
Frenulum – A thin fold of
tissue that is attached
anteriorly to the floor of the
mouth.
The tongue moves food in
the
mouth
and,
in
cooperation with the lips
and cheeks, holds the food
in place during mastication.
It is a major sensory organ
for taste, as well as being one
of the major organs of
speech.
7. TEETH
Normal adult teeth: 32 teeth
It is divided into quadrants:
right upper, left upper, right
lower and left lower.
Each quadrant contains: one
central and one lateral
incisor, one canine, first and
second
premolars
and
first, second and third
molars.
The third molars are called
wisdom teeth because they
usually appear in a person’s
late teens or early twenties.
8. TEETH
The teeth of adults are permanent, or
secondary teeth.
Most of them are replacements of the 20
primary or deciduous teeth which are lost
during childhood.
Each tooth consists of a crown with one or
more cusps, a neck and a root.
Pulp cavity – the center of the tooth which is
filled with blood vessels, nerves and
connective tissue, called pulp.
Dentin – A living, cellular, bonelike tissue
surrounding the pulp cavity.
Enamel – An extremely hard, acellular
substance covering the dentin of the tooth
crown. It protects the tooth against abrasion
and acids produced by bacteria in the mouth.
9. TEETH
Cementum – is the covering of the
surface of the dentin in the root which
helps anchor the tooth in the jaw.
The teeth are rooted within alveoli along
the alveolar processes of the mandible
and maxillae.
The alveolar processes are covered by
dense fibrous connective tissue and
moist stratified squamous epithelium,
referred to as gingiva or gums.
The teeth are held in place by
periodontal ligaments, which are
connective tissue fibers that extend from
the alveolar walls and are embedded into
the cementum.
10. PALATE AND TONSILS
The palate or roof of the oral cavity,
consists of two parts:
Hard Palate – the anterior part that
contains bone
Soft Palate – the posterior portion
that consists of skeletal muscle and
connective tissue
Uvula – is a posterior portion of the soft
palate.
The palate separates the oral cavity from
the nasal cavity and prevents food from
passing into the nasal cavity during
chewing and swallowing.
Tonsils – are located in the lateral
posterior walls of the oral cavity in the
nasopharynx, and in the posterior surface
of the tongue.
11. SALIVARY GLANDS
There are three pairs of salivary
glands:
Parotid,
submandibular and
sublingual glands.
They produce saliva, which is a
mixture of serous and mucous fluids.
Saliva helps keep the oral cavity moist
and contains enzymes that begin the
process of chemical digestion.
The salivary glands have branching
ducts with clusters of alveoli,
resembling grapes, at the ends of the
ducts.
13. SALIVARY GLANDS
PAROTID GLAND
Largest of the salivary glands
Are serous glands located just anterior to each ear.
Parotid ducts enter the oral cavity adjacent to the second upper molars.
SUBMANDIBULAR GLANDS
Produce more serous than mucous secretions.
The submandibular ducts open into the oral cavity on each side of the
frenulum of the tongue.
SUBLINGUAL GLANDS
The smallest of the three paired salivary glands, produce primarily mucous
secretions.
They lie immediately below the mucous membrane in the floor of the oral
cavity.
Each sublingual gland has 10-12 small ducts opening onto the floor of the
oral cavity.
Notes de l'éditeur
-when the person is old enough to have acquired some degree of wisdom.