Session 8: Oral Cavity, Tongue & Pharynx Flashcards
Lateral walls of the oral cavity.
Buccinator
Roof of the oral cavity.
Hard and soft palate
Floor of the oral cavity.
Muscles like two mylohyoid, the tongue and other soft tissues.
Where does the oral cavity begin?
At the oral fissure
Where does the oral cavity end?
At the oropharyngeal isthmus
Explain what the oropharyngeal isthmus is.
An arch formed by the soft palate above and the upper surface of the tongue below.
The sides of the oropharyngeal isthmus are formed by the anterior and posterior pillars of the fauces.
What are the anterior and posterior pillars of the fauces formed by?
The palatoglossus (anterior) and the palatopharyngeal (posterior) muscles.
Action of the palatoglossus and the palatopharyngeal.
Pulls the soft palate down towards the back of the tongue during chewing. This is important for closing the oropharyngeal isthmus in order for food to remain in the oral cavity while chewing.
What lies between the pillars?
The tonsillar fossa
What can be found in the tonsillar fossa?
The palatine tonsils.
What are the classifications of muscles in the tongue?
Intrinsic muscles
Extrinsic muscles
Explain the action of the intrinsic muscles.
Found within the tongue and run longitudinally, vertically and transversely.
They alter the shape of the tongue.
What are the extrinsic muscles of the tongue?
Genioglossus
Hypoglossus
Styloglossus
Palatoglossus
Innervation of the extrinsic muscles of the tongue.
Genioglossus - Hypoglossal nerve
Hyoglossus - Hypoglossal nerve
Styloglossus - Hypoglossus nerve
Palatoglossus - Vagus nerve
Action of the extrinsic muscles of the tongue.
Protraction, retraction and side to side movement of the tongue.
Which muscle is the most important in the tongue, and why?
The genioglossus as its contraction causes protraction of the tongue and its action is therefore used to determine the hypoglossal nerve function. Patient should stick out their tongue.
Special sensory (taste) of the tongue.
Anterior 2/3rds by the facial nerve (Chordae tympani)
Posterior 1/3rd by the glossopharyngeal nerve
General sensation of the tongue.
Anterior 2/3rd by the trigeminal nerve Vc lingual branch
Posterior 1/3rd by the glossopharyngeal nerve
How can you test the vagus nerve by the tongue?
The patient is asked to open their mouth and say ‘ahhh’.
Upon this the uvula to see if there is any deviation to one side of the uvula.
Deviation of the uvula to one side will indicate weakness of the contralateral soft palate (opposite).
You can also test the gag reflex (afferent CN IX, efferent CN X)
Through what does the parotid gland’s saliva enter the oral cavity?
The stensen duct.
Through what does the submandibular gland’s saliva enter the oral cavity?
Wharton duct
What is sialolithiasis?
Salivary gland stones
Where can most sialolithiases be found?
In the submandibular glands
Signs and symptoms of sialolithiasis.
Dehydration and reduced salivary flow.
Pain in gland
Swelling
Infection
Increased pain on salivating and eating.
Most stones are less than 1cm in diamater.
Diagnosis of sialolithiasis.
History
X-ray
Sialogram
What is tonsillitis?
Inflammation of the palatine tonsils

Signs and symptoms of tonsillitis.
Fever
Sore throat
Pain and difficulty swallowing
Cervical lymph nodes
Bad breath
Uvula remains central and no deviation
Pathogens causing tonsillitis.
Viral causes (most common)
Less common is bacterial and due to Streptococcus pyogenes
Signs and symptoms of peritonsillar abscess.
Severe throat pain
Fever
Bad breath
Drooling
Difficulty opening mouth due to pain
‘Hot potato voice’
Deviated uvula
Quinsy

Causes of peritonsillar abscess.
Can follow on from an untreated or partially treated tonsillitis.
Can arise on its own by aerobic or anaerobic bacteria.
Upon examination of tonsillitis and peritonsillar abscess what do you need to watch out for?
Epiglottitis.
It also causes sore throat and fever.
However if you poke around in the mouth and it turns out the patient has epiglottitis they epiglottis might shut. This will shut the airways and the patient can go into respiratory arrest.
Boundaries of the nasopharynx.
Superiorly the base of the skull to the superior border of the soft palate.
Posteriorly C1 and C2
Anteriorly the nasal cavity

What does the nasopharynx contain?
The pharyngeal tonsil
What are the pharyngeal tonsil also called?
The adenoid
Complications of pharyngeal tonsils.
Can block the eustachian tube and cause recurrent and persisent middle ear infections.
Snoring and sleep apnoea
Nasal tone to voice
Can cause chronic sinusitis
Might sleep with mouth open
Boundaries of the oropharynx.
Soft palate to epiglottis
Anterior the oral cavity can be found
Posteriorly C2 and C3

What does the oropharynx contain?
The palatine tonsils
Boundaries of the laryngopharynx?
Oropharynx superiorly to the oesophagus inferiorly.
Epiglottis to the cricoid cartilage.
Anteriorly the larynx can be found.
Posteriorly C4, C5, and C6
What of clinical significance does the laryngopharynx contain?
The piriform fossa
What muscles groups can be found in the pharynx?
The internal pharyngeal muscles and the external constrictors.
What are the internal muscles of the pharynx?
Three longitudinal muscles
Stylopharyngeus
Palatopharyngeus
Salpingopharyngeus
Action of the internal muscles of the pharynx.
Shorten and widen the pharynx as well as elevate the pharynx and larynx during swallowing.
Origination and insertion of stylopharyngeus
Styloid process to the posterior border of the thyroid cartilage
Innervation of the stylopharyngeus.
Glossopharyngeus nerve
Origination and insertion of palatopharyngeus.
Hard palate to the posterior border of the thyroid cartilage.
Innervation palatopharyngeus.
Pharyngeal branch of the vagus nerve
Origination and insertion of salpingopharyngeus.
Cartilaginous part of the eustachian tube. It inserts by merging with the palatopharyngeus.
Innervation of the salpingopharyngeus.
Pharyngeal branch of the vagus nerve
What are the pharyngeal constrictors (external)?
3 circular muscles.
Superior pharyngeal constrictor
Middle pharyngeal constrictor
Inferior pharyngeal constrictor
Action of the pharyngeal constrictors.
Constricts the wall of the pharynx when swallowing.
Insertion of the pharyngeal constrictors.
The pharyngeal raphe
Origin of the SPC
Pterygomandibular raphe
Origin of the MPC
Hyoid bone
Origin of the IPC
2 parts - Thyropharyngeal (thyroid cartilage)
Cricopharyngeal (Cricoid cartilage)
Innervation of the pharyngeal constrictors.
Vagus nerve
What is important to note about the inferior pharyngeal constrictors (the two parts)?
That there is a weakness between the two parts of the the inferior constrictor.
What is the weak area of the inferior constrictor called?
Killian’s dehiscence.
Explain why the Killian’s dehiscence is important to be aware of.
Because during swallowing increased pressure within the pharynx can rise due to the pressure of the inferior constrictors.
Pharyngeal mucosa can therefore herniate through Killian’s dehiscence.
This forms a pharyngeal pouch also called a pharyngeal diverticulum.
Complications of pharyngeal diverticulum.
As food passes thorugh the pharynx, some of the food may become trapped in the diverticulum.
What signs and symptoms might a foreign body stuck in a pharyngeal diverticulum cause?
Bad breath
Regurgitation of food
Occasional choking on fluids
General difficulty swallowing
Where can the pharyngeal plexus be found?
Located mainly on the surface of the middle constrictor muscle.
Motor innervation of the pharyngeal muscles.
CN X innervates all except for stylopharyngeus which is innervated by the glossopharyngeal nerve.
Sensory innervation of the pharynx.
Nasopharynx - maxillary nerve CN V2
Oropharynx - glossopharyngeal nerve
Laryngopharynx - vagus nerve
What elevates the larynx?
The suprahyoid muscles and the longitudinal pharyngeal muscles
Give common causes of dysphagia.
Stroke
Progressive neurological disease like Parkinson’s and MS
COPD
Dementia
Signs and symptoms of dysphagia.
Coughing
Choking
Recurrent pneumonia
Change in voice and speech also called wet voice
Nasal regurgitation
Obvious signs upon examination of cranial nerve IX and X lesions.
Absent gag reflex
Uvula deviated away from the lesion.

Signs of cranial nerve lesions of the CN IX and CN X.
Dysphagia
Taste impairment of the posterior tongue
Loss of sensation of the oropharynx and the laryngopharynx.
Absent gag reflex
Uvula deviation
Causes of cranial IX and X lesions.
Medullary infarct
Jugular foramen problems
Signs and symptoms of cranial nerve XII lesions.
Wasted tongue
When tongue is sticking out the tongue may deviate.
The deviation will be towards the lesion (pointing)
Muscles wasting
Twitching of the tongue called fasciculations.