The Oral Cavity

Flashcards covering the anatomy, divisions, structures, innervation, glands, muscles, and clinical relevance of the oral cavity as presented in the lecture notes.

What is the oral cavity also known as and where is it located?

Also known as the mouth or buccal cavity; located in the lower part of the head, below the nasal cavities.

Between which anatomical landmarks does the oral cavity span?

From the oral fissure anteriorly to the oropharyngeal isthmus posteriorly.

Which structures are necessary for mastication and speech found in the oral cavity?

Teeth, tongue, and salivary glands.

Which bones form the bony framework of the oral cavity?

Paired maxillae, palatine, and temporal bones; and unpaired mandible, sphenoid, and hyoid bones.

What are the major functions of the oral cavity?

Digestion, communication, and breathing.

How is the oral cavity divided and what are the two divisions called?

Into vestibule and oral cavity proper by the upper and lower dental arches.

What is the vestibule in the oral cavity?

The horseshoe-shaped area anteriorly between the lips/cheeks and the gums/teeth.

What is the oral cavity proper?

The inner, larger part posterior to the vestibule; bounded by roof, floor, and lateral walls; the tongue occupies a large portion.

What is the hard palate and its mucosal coverings?

A bony plate anteriorly that separates the nasal cavity from the oral cavity; its superior surface is lined by respiratory mucosa (ciliated pseudostratified columnar) and its inferior surface by oral mucosa (stratified squamous).

What is the soft palate and its function?

A muscular posterior continuation of the hard palate; acts as a valve, lowering to close the oropharyngeal isthmus and elevating to separate the nasopharynx from the oropharynx.

Where does the parotid gland duct open and what is its function?

Opens in the vestibule opposite the upper second molar; secretes saliva.

What are the major salivary glands of the oral cavity?

Parotid, submandibular, and sublingual glands.

What does saliva do for the oral cavity?

Lubricates the inside of the oral cavity and contains enzymes that start carbohydrate digestion.

Name the muscles of the soft palate.

Tensor veli palatini, Levator veli palatini, Palatopharyngeus, Palatoglossus, Musculus uvulae.

What are the palatal arches and what do they connect?

Palatoglossal arch (to the tongue) and Palatopharyngeal arch (to the pharynx).

What connects the tongue to the floor of the mouth?

The frenulum of the tongue.

What structures form the floor of the oral cavity?

Muscular diaphragm with the mylohyoid muscles; geniohyoid; tongue via the frenulum; salivary glands and ducts.

What forms the cheeks and how are they innervated?

Buccinator muscle; innervated by buccal branches of the facial nerve (CN VII).

What are the gingivae (gums) and their parts?

Gums; free part around the neck of the tooth and attached part fixed to the alveolar arch.

What is the periodontal membrane and its relation to the gums?

The fibrous tissue of the gum is continuous with the periosteum lining the alveoli (periodontal membrane).

Which nerve provides sensory innervation to the upper parts of the oral cavity?

Maxillary nerve (V2) of the trigeminal nerve (CN V).

Which nerve provides sensory innervation to the lower parts of the oral cavity?

Mandibular nerve (V3) of the trigeminal nerve (CN V).

Which nerve provides taste to the tongue?

Chorda tympani, a branch of the facial nerve (CN VII).

How are parasympathetic fibers distributed to the glands within the oral cavity?

Via branches of the facial nerve (CN VII), distributed through branches of the trigeminal nerve.

From which spinal level do sympathetic fibers to the oral cavity originate, and where do they synapse?

T1 spinal cord segment; synapse in the superior cervical sympathetic ganglion; distributed along trigeminal branches or with blood vessels.

What is the gag/pharyngeal reflex and which nerve is primarily involved in the afferent limb?

Protective airway reflex; triggered by touching the posterior oral cavity; afferent limb via glossopharyngeal nerve (CN IX).

What are the components of the gag reflex arc?

Contraction of the pharyngeal muscles, elevation of the soft palate, and closure of the glottis.

What is the clinical significance of the gag reflex?

Used to assess brainstem function; absent or diminished in stroke, brainstem injury, or neurodegenerative diseases.

Which muscle controls the diameter of the oral fissure?

Orbicularis oris.

Why are the buccinator and tongue important during chewing?

Buccinator keeps food between the teeth as the tongue manipulates and positions food.

What lines the interior of the cheeks?

Oral mucous membrane.

How are the gums related to the alveolar processes and periosteum?

Gums envelope the alveolar processes; the attached gum is fixed to the alveolar arch; fibrous tissue is continuous with the periosteum (periodontal membrane).

Where is the opening of the parotid duct located?

In the vestibule of the mouth opposite the upper second molar.

Where are the openings of the sublingual gland located?

On the floor of the mouth along the sublingual folds.

What epithelium lines the superior surface of the hard palate?

Respiratory mucosa (ciliated pseudostratified columnar epithelium).

What epithelium lines the oral mucosa on the inferior surface of the hard palate?

Oral mucosa (stratified squamous epithelium).