Oral Cavity and Tongue Flashcards
What are the boundaries of the oral cavity?
Roof: hard palate and soft palate
Floor: muscular diaphragm of tongue and other soft tissues
Lateral walls: buccinators or cheek muscles
Anterior: oral fissure
Posterior: oesophageal isthmus
What is the oral vestibule and the oral cavity proper?
The oral vestibule = space between teeth and cheeks/lips
Oral cavity proper = from teeth to the ring made by the palatopharyngeal arch, the uvula and the tip of the epiglottis.
What forms the hard palate?
The Hard palate is formed by the maxilla and the palatine bones note the same as the bones that form the floor of the nasal cavity.
What forms the soft palate?
This is a muscular structure. Palatoglossus and palatopharyngeus help form the anterior and posterior arches. The palatoglossus forms the palatoglossal (anterior) arch. Palatopharyngeus forms the Palatopharyngeal (posterior) arch. Tense and elevate the soft palate during swallowing and yawning. Between these two arches lies the tonsillar fossa where the palatine tonsils sit.
What is the muscular innervation to the soft palate?
Predominantly vagus nerve via the pharyngeal branch. If damaged, the stronger side is unopposed. Therefore, pulls the uvula away from the side of the affected nerve.
Describe the function and nerves involved in the gag reflex?
Important in preventing choking. Part of the cranial nerve examination. Not done routinely as unpleasant for patient. Important for assessing brainstem function. Afferent limb: Glossopharyngeal to the back of tongue/throat, uvula, tonsillar area. Efferent limb: Vagus to the Pharyngeal muscles of the soft palate.
What supplies sense to the teeth?
Lower jaw has supply from the inferior alveolar nerve. Branch of CN V3. Can lose sensation during mandibular fracture. Site of anaesthesia use in dental surgery.
What are the names of all the teeth?
Central incisor Lateral incisor Canine 2 x pre-molar 2/3 x molar
Describe the 4 intrinsic muscles of the tongue
There are 4 intrinsic muscles that lie entirely within the tongue and run longitudinally, vertically and transversely; they are named according to the direction in which they travel and act to alter the shape of the tongue. The intrinsic muscles are not attached to bone but blend with the extrinsic muscles.
Describe the 4 extrinsic muscles of the tongue
The four extrinsic muscles act to change the position of the tongue but also anchor it to the surrounding structures i.e. the hyoid bone and mandible below, and the styloid process and soft palate above. All muscles of the tongue are innervated by the hypoglossal nerve (CN XII), except the palatoglossus, which is innervated by the vagus nerve (CN X).
What direction does the uvula and tongue move when there are neural lesions?
In neural lesions to the uvula and Tongue the unaffected side dominates! Normal tongue muscle overpowers weakened muscle on affected side. Therefore: – Uvula deviation = away from the side of the lesion – Tongue deviation = towards the side of the lesion.
Describe where the parotid and submandibular glands open into the oral cavity?
Parotid and submandibular glands enter oral cavity through a single opening. Parotid duct = Stenson’s duct. Submandibular = Wharton’s duct Sublingual gland opens via multiple ducts. Sublingual has many opening under the tongue.
Describe how salivary stones present?
Saliva can crystallise and block the salivary ducts these are usually calcium-based. Most commonly affects the submandibular duct as it produces saliva that is comparatively thicker than parotid gland. Sublingual stones very rare. Commonly presents as pain or swelling of the affected gland at meal times. May be able to see a Wharton’s duct stone. Small stones may resolve spontaneously, commonly need removal.
What is tonsillitis and how can you tell the difference between bacterial and viral?
Inflammation of the palatine tonsil. Patients often present with sore throat and odynophagia/dysphagia if severe. Tonsils are typically enlarged and erythematous. Usually infective: Viral e.g. rhinovirus, adenovirus, accompanied by symptoms of URTI e.g. dry cough. Bacterial e.g. beta-haemolytic strep, accompanied by cervical lymphadenopathy, fever, absence of a cough and pus.
What is a peritonsillar abscess (‘quinsy’) and why is it dangerous?
Severe complication of bacterial tonsillitis usually due to strep pyogenes. Other organisms include staph aureus, H. influenza or a mixed flora. Patients typically systemically unwell with trismus or ‘hot potato voice’. May appear to be drooling due to dysphagia. Often unilateral and the uvula can deviate away from the lesion. Requires immediate referral to ENT.
