Anatomy - Oral Cavity Flashcards
What are the 2 divisions of the oral cavity?
The vestibule and the mouth cavity proper
What is the vestibule?
The space between the lips/cheeks and the gums/teeth
The diameter of the oral fissure is controlled by the muscles of facial expression, principally the…
Obicularis oris
Opposite the seconds molar tooth, the duct of what gland opens into the vestibule?
Parotid
What comprises the roof of the mouth proper?
Hard and soft palates
Is the hard or soft palate found anteriorly?
Hard is anterior
Describe the soft palate
Posterior continuation of hard palate
A muscular structure
Acts as a valve that can lower to close the oropharyngeal isthmus and elevate to separate the nasopharynx from oropharynx
What does the floor of the oral cavity consist of?
Tongue
Geniohyoid muscles - pull larynx forward during swallowing
Muscular diaphragm- the bilateral mylohyoid muscles (structural support and pulls larynx forward during swallowing)
Salivary glands and ducts
What connects the tongue to the floor of oral cavity?
Frenulum - a fold of oral mucosa
The cheeks are formed by what muscle?
Buccinator
What is the role of buccinator muscle?
Contracts to keep food between teeth when chewing
The tongue has extrinsic and intrinsic muscles. What does this mean?
Extrinsic - insert into tongue
Intrinsic - shape the tongue
What muscles make up the intrinsic tongue?
Superior longitudinal
Transverse
Vertical
Inferior longitudinal
What is the motor innervation for the intrinsic muscles of the tongue?
Hypoglossal nerve CN XII
How many extrinsic tongue muscles are there?
4
What are the extrinsic tongue muscles?
Genioglossus
Hypoglossus
Styloglossus
Palatoglossus
What is the role of the styloglossus muscle?
Retraction and tongue elevation
What is the motor innervation of genioglossus, hypoglossus and styloglossus?
Hypoglossal nerve CNXII
What is the motor innervation for palatoglossus?
Vagus nerve (pharyngeal branch)
What is the role of palatoglossus?
Initiates swallow by elevating tongue and lowering soft palate of mouth
What supplies general sensation to anterior 2/3 of tongue?
Trigeminal nerve - lingual branch of mandibular division
What supplies taste sensation to anterior 2/3 of tongue?
Facial nerve - specifically the chorda tympani branch
What nerve supplies both general sensation and special sensation (taste) to posterior 1/3 or tongue?
Glossopharyngeal nerve CNIX (lingual branch)
What are the salivary glands?
Sunbmandibular
Sublingual
Parotid
The submandibular gland hooks around which muscle?
Mylohyoid muscle
What are the submandibular ducts called?
Wharton’s ducts
Where do the submandibular ducts open?
Under the tongue, at the base of the lingual frenulum bilaterally
What type of saliva does the parotid gland produce?
Serous saliva - watery and rich in enzymes
Lubricates and breaks down food
The deep and superficial loves of the parotid gland are divided by which nerve?
Facial nerve
The secretions from parotid gland are transported via what duct?
Stensen duct - transverses the masseter muscle, then pierces the buccinator
Where does the parotid Stensen duct open in the oral cavity?
Near the second upper molar
What artery ascends through the parotid gland?
External carotid artery - within the gland it gives rise to the posterior auricular artery
Sensory innervation to the parotid gland is supplied by…
The auriculotemporal nerve (branch of mandibular nerve)
The great auricular nerve supplies the fascia of the gland
What supplies the parasympathetic innervation to the parotid gland?
Glossopharyngeal nerve
This synapses with otic ganglion, the auriculotemporal nerve then carries parasympathetic fibres to parotid gland
What supplies parasympathetic innervation to the submandibular and sublingual glands?
Facial nerve - the chorda tympani unifies with the lingual branch of the mandibular nerve before synapsing at the submandibular ganglion. Post ganglionic innervation consists of secretory motor fibres which directly induce gland to produce secretions
What are the smallest of the 3 paired glands?
Sublingual glands
And most deeply situated
What type of secretions do the sublingual glands produce and how much?
Mixed - predominantly mucus in nature
Contribute 3-5% of overall salivary volume
Where are the sublingual glands located?
Lie on floor of oral cavity, under tongue
Multiple ducts release the saliva
What type of secretions do the submandibular glands produce?
Mixed serous and mucus
The parotid gland lies anterior to what and lateral to what?
Anterior to pinna
Lateral to ramus of mandible
What is one of the most serious risks from parotid surgery?
Facial nerve palsy
80% of salivary gland neoplasms occur in which gland?
Parotid
Infections in the submandibular gland are how many times more common than in the parotid ?
9x
