2. Oral cavity. Lips. Cheeks. Hard and soft palate, salivary glands, tongue.

what are the points

• oral cavity

• lips

• cheeks

• sailvary glands

• palate

• tongue

oral cavity

Oral cavity (the mouth) extends from the lips to the pharynx. 3 functions:

• -  digestion (receives and prepares food for digestion) aided by salivary glands

• -  communication (modifies the sound produced by the larynx)

• -  breathing (acts as air inlet in addition to the nasal cavity)

  Oral region structures include:

• -  oral cavity

• -  teeth

• -  gingiva

• -  tongue

• -  palate (soft and hard)

• -  region of palatine tonsils

  The oral cavity is divided into two divisions: vestibule and the oral cavity proper:

  V estibule

• -  vestibule is a slit-like space between the cheeks and the gums.

• -  communicates with the exterior through the oral fissure and communicates with the

  oral cavity proper behind the 3rd molar tooth.

• -  lateral wall of the vestibule is formed by the cheek which is composed of buccinator

  muscle (covered laterally by the skin and medially by the mucous membrane)

• -  opposite the upper 2nd molar tooth, on the mucosa is the opening of the duct of the

  parotid gland

• -  blood supply: via branches of the external carotid artery (facial, maxillary, and

  lingual)

  Oral cavity proper

• -  is interior to the alveolar margins of the maxilla and the mandible

• -  the roof is formed by the hard palate (anterior) and soft palate (posterior)

• -  the floor is formed by the mylohyoid muscle (anterior 2/3rd of the tongue lies on the

  floor)

salivary glands

• parotid gland:

• -  largest salivary gland

• -  found wrapped around the mandibular ramus and secretes saliva through the Stensens

  duct into oral cavity to facilitate mastication and swallowing

• -  duct enters the oral cavity opposite the 2nd upper molar

• serous secretion

  submandibular gland

• -  they are paired glands located beneath the lower jaw’s superior to digastric muscles

• -  approx. 70% of saliva is produced by submandibular gland

• -  secretion is a mixture of serous and mucus fluid

  sublingual gland

• -  they are paired glands located under the tongue

• -  mainly mucous secretion, however categorized as a mixed gland

• -  Approx. 5% of saliva is produced by these glands

lips

• Form the front (anterior) boundary of the oral cavity.

• Involved in speech, facial expressions, and food intake.

• Contain muscles - obicularis oris, depressor anguli oris,

cheeks

• Form the lateral walls of the oral cavity.

• Made up of muscles (mainly the buccinator), fat, and skin.

• Help in chewing by keeping food between the teeth.

palate

•  Forms the roof of the oral cavity and the floor of the nasal cavity

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• -  The hard palate separated the oral cavity from the nasal cavity

• -  The soft palate separates the oropharynx from the nasopharynx

• -  Hard palate is situated anteriorly, and the soft palate is situated posteriorly

• Hard palate (anterior): bony structure aiding in speech and food manipulation.

• Soft palate (posterior): muscular and flexible, assists in swallowing by closing off the nasal passage.

tongue

it’s a highly specialised structure with various functions including taste, organ of

speech and assists in mastication and deglutition of food Lingual papilla: essential for taste perception as they contain taste buds

• -  Fungiform papilla

• -  Foliate papilla

• -  Filiform papilla

• -  Circumvallate papilla

• • • •

Superior longitudinal fibers: shorten the tongue. I

nferior longitudinal fibers: shorten the tongue.

Vertical fibers: flatten and widen the tongue.

Transverse fibers: narrow and elongate the tongue.

Extrinsic muscles: • Genioglossus
• Hyoglossus
• Styloglossus

• Palatoglossus

hypoglossal nerve innervates it obvi