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1. ORAL CAVITY
By
Himanshu
Group no:-313
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2. Oral cavity
🠶 Structure of oral cavity
1. Mouth
2. Teeth
3. Gums
4. Cheeks
5. Lips
6. Palate
7. Tounge
🠶 Oral mucosa
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3. Oral cavity(Mouth)
🠶 The oral cavity, better known as the mouth, is the start of the alimentary canal.
🠶 It has three major functions:
🠶 Digestion – receives food, preparing it for digestion in the stomach and small
intestine.
🠶 Communication – modifies the sound produced in the larynx to create a range of
sounds.
🠶 Breathing – acts as an air inlet in addition to the nasal cavity.
🠶 STRUCTURE
🠶 Extends from the lips to the oropharyngeal isthmus.
🠶 The oropharyngeal isthmus: Is the junction of mouth and pharynx.
🠶 Is bounded:
Above by the soft palate and the palatoglossal folds
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4. Structure of oral cavity
🠶 Oral cavity consists of two parts :
🠶 A.Oral vestibule
Boundaries :
1.Antereriorly by lips
2.laterally by cheeks
3.Posteriourly and medially by teeth and gums
🠶 B.Oral cavity proper
Boundaries :
1.Anteriorly laterally by teeth and gums
2.superiourly by the palate
3.Inferiorly by the tounge and the floor ot the
mouth
4.Posteriorly by opening into the pharynx.
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5. Tongue
🠶 Mass of striated muscles covered with the mucous membrane.
🠶 Divided into right and left halves by a median septum
🠶 Three parts:
Oral (anterior 2/3rd)
Pharyngeal(posterior1/3)
Root (base)
🠶 Two surfaces:
Dorsal
Ventral
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6. Sensory and motor nerve supply
🠶 Sensory nerves:
Anterior 2/3:
General sensations: Lingual nerve
Special sensations : chorda tympani
Posterior :. General & special sensations
glossopharyngeal nerve
Base:. General & special sensations internal
laryngeal nerve
🠶 Motor nreves:
Intrinsic muscles: ▪ Hypoglossal nerve
Extrinsic muscles:- All supplied by the
hypoglossal nerve,except the palatoglossus.
The palatoglossus supplied by the pharyngeal plexus
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7. Functions:
🠶 The tonge is the most important articulator for speech production.
🠶 During speech, the tongue can make amazing range of movements.
🠶 The primary function of the tongue is to provide a mechanism for
different areas of the tongue, but are generally found around the
edges.
🠶 They are sensitive to taste. Taste buds are located on four main
tastes: Bitter, Sour,Salty & Sweet.
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8. Teeth
The teeth are the hardest substances in the human body. Besides being essential for
chewing, the teeth play an important role in speech. Parts of the teeth include:
• Enamel: The hardest, white outer part of the tooth.. Enamel is mostly made
of calcium phosphate, a rock-hard mineral.
• Dentin: A layer underlying the enamel. It is a hard tissue that contains microscopic
tubes. When the enamel is damaged, heat or cold can enter the tooth through these
paths and cause sensitivity or pain.
• Pulp: The softer, living inner structure of teeth. Blood vessels and nerves run
through the pulp of the teeth.
• Cementum: A layer of connective tissue that
binds the roots of the teeth firmly to the
gums and jawbone.
• Periodontal ligament: Tissue that helps
hold the teeth tightly against the jaw. 08

9. 🠶 A normal adult mouth has 32 teeth, which (except for wisdom teeth ) have
erupted by about age 13:
• Incisors (8 total): The middlemost four teeth on the upper and lower jaws.
• Canines (4 total): The pointed teeth just outside the incisors.
• Premolars (8 total): Teeth between the canines and molars.
• Molars (8 total): Flat teeth in the rear of the mouth, best at grinding food.
• Wisdom teeth or third molars (4 total): These teeth erupt at around age 18,
but are often surgically removed to prevent displacement of other teeth.
🠶 Functions:
Mastication
Speech
Appearance
Growth of jaws
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10. Hard palate
🠶 The hard palate is the horizontal bony plate that makes a subsection of the palate of
the mouth. It makes the anterior two-thirds of the roof of the oral cavity.
🠶 The hard palate is made of two facial bones: palatine process of the maxilla and
paired palatine bones.
🠶 Borders:
The anterior portion of the palate is bordered anteriorly and
laterally by the maxillary teeth.
Superiorly it is covered by the respiratory epithelium cavity and
inferiorly by the masticatory epithelium of the oral cavity.
Posteriorly, the hard palate is connected to the soft palate.
🠶 Functios:
Feeding
Speech
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11. Structure:
🠶 The hard palate separates the oral and nasal cavities.
🠶 Its bony structure is comprised of three cranial bones, the maxilla and the
paired palatine bones.
🠶 Anteriorly, the palatine process of the maxilla is situated, covering the area
between the two sides of the maxillary dental arch.
🠶 In the anterior midline, the incisive foramen can be found, which sits just below
the incisive papilla that is a fleshy convexity on the palatal mucosa.
🠶 Posterolaterally, one centimeter medial
from the second maxillary molar, the greater
and lesser palatine foramina can be found.
🠶 Deep in the palatal mucosa are hundreds
of mucous secreting salivary glands .
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12. Soft palate
🠶 The soft palate, also known as velum, is a mobile fold of soft tissue attached to the posterior margin of the
hard palate . It extends posteroinferiorly, being leveled with the border between the nasopharynx and
oropharynx.
🠶 It is distinguished from the hard palate by having
a darker red color with a yellowish tone.
Lying between the oral and nasal cavities,
the soft palate features the oral and nasal surfaces.
🠶 The oral surface is covered by the non-keratinized
stratified squamous epithelium with secretory
salivary glands.
🠶 The nasal surface is lined by the simple ciliated
columnar epithelium (respiratory epithelium) and it
is continuous with the floor of the nasal cavity.
🠶 The four borders of the soft palate are the anterosuperior, two lateral, and an inferoposterior border.
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13. Lips
These are two fleshy folds that circumscribe the mouth and closes the cavity.
🠶 Two Lips Upper Lip and LowerLip
🠶 The Corner of the mouth where the two lips meet is called Commissure.
🠶 Two Grooves are distinguished around lips.
Nasolabial groove
Labiomental groove.
🠶 FIVE LAYERS
1. Skin-contains hair follicles and sebaceous glands
2. Superficial Fascia- contains some fats
3. Orbicularis Oris muscle - serves as sphincter of the mouth
4. Submucous tissue - contains vessels, mucous labial glands and labial branches offacial
artery
5. Mucous membrane - innermost layer
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14. Cheeks(Buccal mucosa)
🠶 The cheeks are formed by the buccinator muscle, which is lined internally by
the oral mucous membrane.
🠶 The buccinator muscle contracts to keep food between the teeth when
chewing, and is innervated by the buccal branches of the facial nerve (CN
VII).
🠶 It consists of stratified squamous epithelium ,lamina propria and submucosa.
🠶 Submucosa of cheeks contain fat
cells along with lobules of minor salivary
glands and muscle fibres.
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15. Gums(Gingivae)
🠶 They surround the teeth and cover the upper and lower alveolar ridges.
🠶 The gingiva is composed of an outer epithelium
and an inner network of connective tissue.
This outer epithelial layer is keratinized, forming
a protective layer around the tooth.
Contained within the inner gingival connective
tissue are gingival fibroblasts, which play
a crucial role in tissue repair and the
inflammatory response.
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16. ORAL MUCOSA
🠶 Mucous Membrane:
Moist lining of the gastrointestinal tract, nasal passages and other body cavities
that communicate with the exterior.
In the oral cavity the lining is called as oral mucous membrane or oral mucosa.
🠶 Functions of the Oral Mucosa1:
Protection: Barrier for mechanical trauma and microbiological insults.
Sensation:Temperature (heat and cold), touch, pain, taste buds, thirst; reflexes
such as swallowing, etching, gagging and salivating.
Secretion: Salivary secretion.
Thermal regulation: Important in dogs not in humans
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17. Organization of oral mucosa
🠶 Three types according to FUNCTION:
🠶 1. Masticatory Mucosa: 25% of total mucosa. Gingiva (free, attached
and interdental) and hard palate. Primary mucosa to be in contact with
food during mastication. MASTICATORY MUCOSA IS USUALLY
KERATINIZED.
🠶 2. Lining Mucosa: 60% of total mucosa. Covers the floor of mouth,
ventral (underside) tongue, alveolar mucosa, cheeks, lips and soft
palate. Does not function in mastication and therefore has minimal
attrition. Non-keratinized; soft and pliable.
🠶 3. Specialized Mucosa: 15% of total mucosa. Covers dorsal tongue and
composed of cornified epithelial papillae.
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18. Structure of oral mucosa
🠶 Oral mucosa consists of two layers, the surface stratified squamous epithelium and
lamina propria .
🠶 In keratinized oral mucosa, the epithelium consists of four layers:
Stratum basale (basal layer)
Stratum spinosum (prickle layer)
Stratum granulosum (granular layer)
Stratum corneum (keratinized layer)
🠶 In nonkeratinised epithelium, the two deep
layers ( basale and spionosum) remain the same
but the outer layers are termed the intermediate
and superficial layers.
🠶 Depending on the region of the mouth,
the epithelium may be nonkeratinized or keratinized.
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19. 🠶 Nonkeratinized squamous epithelium covers the soft palate, inner lips, inner cheeks,
and the floor of the mouth, and ventral surface of the tongue.
🠶 Keratinized squamous epithelium is present in the gingiva and hard palate as well as
areas of the dorsal surface of the tongue.
🠶 The lamina propria is a fibrous connective tissue layer that consists of a network of type
I and III collagen and elastin fibers in some regions. The main cells of the lamina propria
are the fibroblasts, which are responsible for the production of the fibers as well as the
extracellular matrix .
🠶 A submucosa may or may not be present deep in the dense layer of the lamina propria,
depending on the region of the oral cavity.
🠶 If present, the submucosa usually contains loose connective tissue and may also contain
adipose tissue or salivary glands , as well as overlying bone or muscle within the oral
cavity.[
🠶 Typically, regions such as the cheeks, lips, and parts of the hard palate contain
submucosa (a layer of loose fatty or glandular connective tissue containing the major
blood vessels and nerves supplying the mucosa).
🠶 A basal lamina is at the interface between the oral epithelium and lamina propria similar
to the epidermis and dermis.
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20. Reference:
🠶 Human anatomy and physiology Textbook by Ross and Wilson
🠶 Human anatomy and physiology Textbook by Tortora
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21. Thank You
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