Session 4: Oral Cavity and Upper GI Tract Flashcards
List the three sets of tonsils found in the upper GI tract
Palatine, Pharyngeal (aka adenoid, located at the back of the nasal cavity) Lingual (at the back of the tongue) tonsils have protective roles (they are lymphatic tissue, they produce antibodies to fight against germs)
Between which two folds do the palatine tonsils lie?
Palatopharyngeal Fold (or arch) Palatoglossal Fold (or arch)
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 are vagus-mediated effects. So the GP is testing the motor function of the vagus nerve.
Describe the borders of the pharynx.
Superior border: Base of the skull and the pharynx extends all the way to 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 – from the epiglottis to the cricoid cartilage
What happens to the epiglottis when you swallow?
Retroflexion (bend backwards) 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 (IX) and Vagus (X) (pharyngeal branch) (these two are part of the pharyngeal plexus)
The pharyngeal plexus lies on the posterolateral wall of the pharynx, mainly over the middle pharyngeal constrictor and is the main motor and sensory nerve supply to the muscles of the pharynx and soft palate and acts to coordinate swallowing and speech. Note that the larynx is not supplied by the pharyngeal plexus, it is supplied by the superior and recurrent laryngeal branches of vagus.
Which nerves provide motor innervation of the pharyngeal constrictor muscles?
Vagus (and a bit of accessory nerve) Accessory nerve is sometimes considered part of the pharyngeal plexus too. (Remember the card about the course of accessory, the cranial accessory fibres are distributed via vagus)
The pharyngeal plexus lies on the posterolateral wall of the pharynx, mainly over the middle pharyngeal constrictor muscle and is the main motor and sensory nerve supply to the muscles of the pharynx and soft palate and acts to coordinate swallowing and speec
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 (aka upper oesophageal sphincter), open oesophagus for food to go down
https: //www.youtube.com/watch?v=YQm5RCz9Pxc
Name the three salivary glands, describe their secretions and state the nerves that provide secretomotor innervation to them.
Parotid – mainly serous – glossopharyngeal
Submandibular (below mandible) – mainly serous – facial
Sublingual (below tongue) – mainly mucous – facial slide 9
Which muscle does the parotid duct pierce and where does it open into the buccal cavity (aka oral cavity)?
Buccinator It opens next to the second upper molar
Name the main muscles of the tongue. Which nerve innervates all of this?
Extrinsic muscles: Genioglossus, Hyoglossus, Styloglossus,palatoglossus
+ Intrinsic Muscles within the tongue
These are all innervated by the HYPOGLOSSAL NERVE (XII) EXCEPT palatoglossus
What other muscle is associated with the tongue but isn’t innervated by this nerve?
Palatoglossus – from the palatine aponeurosis to the tongue, it is innervated by the VAGUS
What tongue movements do the genioglossus and styloglossus perform?
Genioglossus – protracts (prolong, so move the tongue down) the tongue Styloglossus – retracts and elevates the tongue Slide 11- genioglossus is below the tongue so it probably pulls It downwards
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
Lingual nerve is a branch of V3 (mandibular branch of trigemeinal). Responsible for sensory of the anterior 2/3rd of the tongue
Describe the sensory innervation of the tongue
Anterior 2/3 sensation – mandibular branch of trigeminal (lingual nerve)
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.
Nucleus Solitarius
State the origin and insertion of temporalis and the movement that it is responsible for.
Origin: Temporal Fossa (depression on the side of the skull, this depression is not only within the temporal bones but goes beyond and covers parietal and frontal bones)
Insertion: Coronoid Process
Function: 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 pterygoid – lateral pterygoid plate (and greater wing of sphenoid) TO neck of the mandible Medial pterygoid– lateral pterygoid plate, maxilla, palate TO angle of the mandible
Functions: Lateral – Movement – depresses and protracts mandible to open the mouth
Medial – Movement – elevates, protracts and lateral movement of mandible for chewing
State the eight branches of the external carotid artery.
Superior Thyroid
Ascending Pharyngeal
Lingual
Facial
Occipital
Posterior Auricular
Maxillary (which then gives off middle meningeal a.)
superficial temporal
Some Anatomists Like Freaking Out Poor Medical Students (most inferior branch to most superior)
Through which foramen does the middle meningeal artery enter the skull?
Foramen Spinosum (spinosum means spine, it lies next to the spine of the sphenoid bone)
State the five branches of the facial nerve
Temporal Zygomatic Buccal Mandibular Cervical
Two zombies bit my cat
State where these arteries and veins originate from and drain to.
see pic
Superior thyroid artery – from the external carotid artery
Inferior thyroid artery – from the thyrocervical trunk (originates from subclavian)
Superior thyroid vein – to the internal jugular vein
Middle thyroid vein – to the internal jugular vein
Inferior thyroid vein – to the brachiocephalic vein
