Flashcards in Session 4: Oral Cavity and Upper GI Tract Deck (55)
List the three sets of tonsils found in the upper GI tract
Palatine, Pharyngeal, Lingual
Between which two folds do the palatine tonsils lie?
Why does the GP gets you to say ‘aaaaaah’ when he inspects the inside of your mouth?
It raises the soft palate and uvula and depresses the tongue, which arevagus-mediated effects. So the GP is testing the motor function of the vagus nerve.
Describe the borders of the pharynx.
Base of the skull and the inferior border of the cricoid cartilage
What are the three parts of the pharynx and what are their borders?
Nasopharynx – down to the soft palate (pharyngeal isthmus)
Oropharynx – between the soft palate and the epiglottis
Laryngopharynx – between the epiglottis and the cricoid cartilage
What happens to the epiglottis when you swallow?
Retroflexion to cover the laryngeal inlet
What is the role of the soft palate in swallowing?
It elevates to close off the nasopharynx so that food doesn’t go into the nasal cavity
What is the Piriform Fossa and what is its clinical significance?
The piriform fossae are depressions on either side of the laryngeal inlet where food (commonly fish bones) get stuck
Which muscles aid the passage of a bolus of food down the oesophagus?
Superior, middle and inferior pharyngeal constrictor muscles
Which nerves provide sensory innervation of the pharyngeal wall?
Glossopharyngeal and Vagus (pharyngeal plexus)
Which nerves provide motor innervation of the pharyngeal constrictor muscles?
Vagus (and a bit of accessory)
Describe the changes that occur during swallowing.
Lift and retract the tongue (styloglossus and intrinsic muscles)
Bolus into oropharynx (palatoglossus)
Close off nasopharynx by raising soft palate
Raise the larynx – closed off by the epiglottis
Peristaltic wave of constrictor muscles
Relax cricopharyngeus, open oesophagus
Name the three salivary glands, describe their secretions and state the nerves that provide secretomotor innervation to them.
Parotid – serous – glossopharyngeal
Submandibular – serous – facial
Sublingual – mucous – facial
Which muscle does the parotid duct pierce and where does it open into the buccal cavity?
It opens next to the second upper molar
Name the main muscles of the tongue. Which nerve innervates all of this?
Genioglossus, Hyoglossus, Styloglossus
These are all innervated by the hypoglossal nerve
What other muscle is associated with the tongue but isn’t innervated by this nerve?
Palatoglossus – it is innervated by the vagus
What tongue movements do the genioglossus and styloglossus perform?
Genioglossus – protracts the tongue
Styloglossus – retracts and elevates the tongue
To which side would the tongue move if a patient with a unilateral lesion in the hypoglossal nerve was asked to stick their tongue out?
Towards the side of the lesion because the genioglossus is used in protracting the tongue
What movement is palatoglossus responsible for?
Elevates the soft palate and moves the back of the tongue upwards
Where is the lingual nerve relative to the hypoglossal nerve?
Lingual nerve is superior to the hypoglossal nerve
Describe the sensory innervation of the tongue
Anterior 2/3 sensation – mandibular branch of trigeminal
Anterior 2/3 taste – facial
Posterior 1/3 everything – glossopharyngeal
To which structure in the brainstem do the neurons of taste go? It is considered the main taste centre within the brainstem.
State the origin and insertion of the masseter and the movement that it is responsible for.
Lateral surface of the ramus of the mandible and the angle of the mandible
Elevates the mandible (allows forced closure of the mouth)
State the origin and insertion of temporalis and the movement that it is responsible for.
Elevates and retracts mandible
State the origin and insertion of the medial and lateral pterygoid muscles and the movements that they are responsible for.
Lateral – lateral pterygoid plate (and greater wing of sphenoid) TO neck of the mandible
Medial – lateral pterygoid plate, maxilla, palate TO angle of the mandible
Lateral – Movement – depresses and protracts mandible to open the mouth
Medial – Movement – elevates, protracts and lateral movement of mandible for chewing
Describe the structure of the temporomandibular joint.
t is a capsular joint The capsule has an articular plate splitting it into two The head of the mandible articulates with the articular tubercle of the temporal bone
Describe the movements around the temporomandibular joint when opening the mouth.
When opening the mouth slightly there is a hinge action
When the mouth is opened further, the head of the mandible glidesanteriorly on the articular tubercle of the temporal bone
State the eight branches of the external carotid artery.
Superior to Inferior
At the level of what anatomical landmark does the common carotid artery bifurcate.
At the level of the laryngeal prominence