Anatomy of Oral Cavity and Tongue Flashcards
What are the boundaries of the oral cavity?
- Roof
- Floor
- Lateral walls
- Anterior
- Posterior
What is the roof of the oral cavity made up of?
- Hard palate
- Soft palate
What is the hard palate formed by?
The maxilla and palatine bones, the same bones that form the floor of the nasal cavity
What is the soft palate made up of?
Muscles
What do the palatoglossus muscle of the soft palate do?
Forms the palatoglossal (anterior) arch
What does the palatopharyngeus of the soft palate fo?
Forms the palatopharyngeal (posterior) arch
What is the function of the muscles of the soft palate?
To tense and elevate the soft palate during swallowing and yawning
What is the innervation of the soft palate?
Predominantly the vagus nerve
What happens if the vagus nerve is damaged, regarding the soft palate?
The stronger side is unoppsed, and therefore pulls the uvula away from the side of the affected nerve
What forms the floor of the oral cavity?
- Tongue
- Other soft tissues
What forms the lateral walls of the oral cavity?
Cheek
What is the cheek made of?
Buccinator muscles
What forms the anterior walls of the oral cavity?
Oral fissure
What is the oral fissure?
The space between the lips
What forms the posterior boundary of the oral cavity?
The oropharyngeal isthmus
What is the oropharyngeal isthmus?
Opening to oropharynx
What is the oral vestible?
The space between the teeth and the cheek/lips
What is the oral cavity proper?
From the teeth, to the ring made by the palatopharyngeal arch, the uvula, and the tip of the epiglottis
What is the gag reflex important in?
Preventing choking
What is testing of the gag reflex part of?
Cranial nerve examination
Why is testing of the gag reflex not routinely done?
Because it is unpleasant for the patient
Where is testing for the gag reflex important?
For assessing brainstem funciton
What is the afferent limb of the gag reflex?
Sensation from the back of the tongue/throat, uvula, and tonsillar area, provided by glossopharyngeal nerve
What is the efferent limb of the gag reflex?
The vagus nerve, which innervates the pharyngeal muscles on both sides to lift the soft palate
Draw a labelled diagram illustrating the names of the teeth
What is the nervous supply of the lower jaw?
The inferior alveolar nerve
What is the inferior alveolar nerve a branch of?
CN V3
What is the clinical relevance of the inferior alveolar nerve?
- Can loose sensation during mandibular nerve fracture
- Site of anaesthesia use in dental surgery
Why can a mandibular nerve fracture lead to a loss of sensation in the lower jaw?
Because it runs through the mandibular fossa
What are the extrinsic muscles of the tongue?
- Styloglossus
- Genioglossus
- Hyoglossus
- Palatoglossus
What does the styloglossus do?
Retracts and elevates
What does the genioglossus do?
Protrudes tongue
What does the hyoglossus do?
Retracts and depresses
What is the palatoglossus innervated by?
The vagus nerve, because is part of the soft palate
What is the function of the extrinsic muscles of the tongue?
- Help anchor tongue
- Allow tongue to change position
How do the extrinsic muscles of the tongue help anchor the tongue?
Attach tongue to hyoid bone and mandible
What are the intrinsic muscles of the tongue?
- Superior longitudinal
- Vertical
- Transverse
- Inferior longitudinal
What do the superior and inferior longitudinal muscles of the tongue do?
Curl
What does the vertical intrinsic muscle of the tongue do?
Flattens tongue
What does the transverse intrinsic muscle of the tongue do?
Pulls tongue in, making it smaller and round
Draw a diagram illustrating the innervation of the tongue
What happens in pathologies of the nerves supplying the tongue?
The unaffected side dominates- the normal tongue overpowers the weakened muscle on the affected side, so tongue deviation is towards the side of the lesion
How do the parotid and submandibular glands enter the oral cavity?
Through a single opening
What is the opening of the parotid gland into the oral cavity?
Stenson’s duct
What is the opening of the submandibular gland into the oral cavity?
Wharton’s duct
How does the sublingual gland open into the oral cavity?
Via multiple ducts
Where are the ducts of the sublingual glands?
Lateral to frenulum and base of tongue
What are salivary gland stones made of?
Usually calcium-based
How do salivary gland stones aries?
Saliva crystallises and blocks the salivary ducts
Which salivary duct to salivary gland stones most commonly affect?
The submandibular gland
Why is the submandibular gland most commonly affected by salivary gland stones?
Because it produces saliva that is comparatively thicker than parotid gland
How common are sublingual stones?
Very rare
How do salivary gland stones present?
As pain or swelling of the affected gland at meal times
What salivary gland stone may be visible?
Wharton’s duct stone
How are salivary gland stones managed?
Small stones may resolve spontaneously, but they commonly need removal
What is tonsillitis?
Inflammation of the palatine tonsil
How does tonsillitis present?
- Sore throat
- Odonophagia/dysphagia if severe
- Enlarged and erythematous tonsils
Why does tonsillitis cause odonophagia and dysphagia if severe?
Tonsils are so englarged, they are causing a blockage
What causes tonsilltis?
Usually infective
Give two pathogens that commonly cause viral tonsillitis
- Rhinovirus
- Adenovirus
What are the symptoms of viral tonsillitis accompanied by?
The symptoms of UTRI;
- Dry cough
- Run down
- Headaches
What is bacterial tonsillitis most commonly caused by?
ß-haemolytic strep
What are the symptoms of bacterial tonsillitis accompanied by?
- Cervical lymphademopathy
- Fever
- Pus
What happens to the anterior and posterior arches in tonsillitis?
The anterior arch is still present, but the posterior arch is obscured by the enlarged tonsils
What complication can tonsillitis lead to?
Peritonsillar abscess, or ‘quinsy’
What is quinsy caused by?
Usually caused by strep. pyogenes, but other organisms include;
- Staph aureus
- H. influenza
- Mixed flora
What are the symptoms of quinsy?
- Patients systemically unwell
- Trismus
- ‘Hot potato’ voice
- Drooling
What causes trismus and hot potato voice in quinsy?
They don’t want to open their mouth too much
Why may patients with quinsy be drooling?
Because of dysphagia
Is quinsy unilateral or bilateral?
Often unilateral
What happens to the uvula in quinsy?
It can deviate away from the lesion
What happens to the anterior arch in quinsy?
It is lost
How is quinsy managed?
Requires immediate referral to ENT for drainage and antibiotics
