4 - Oral Cavity and Upper GI

Question 1

What is the buccal cavity?

Answer 1

the oral cavity (mouth)

Question 2

List the three sets of tonsils found in the upper GI tract.

Answer 2

Palatine, Pharyngeal, Lingual

Question 3

Between which two folds do the palatine tonsils lie?

Answer 3

Palatopharyngeal Fold

Palatoglossal Fold

Question 4

Why does the GP gets you to say ‘aaaaaah’ when he inspects the inside of your mouth?
What would you expect to see?

Answer 4

It raises the soft palate and uvula and depresses the tongue, which are vagus-mediated effects.
It is to test the motor function of the vagus nerve.

Question 5

When testing for the function of the vagus nerve, what would indicate a problem/lesion with the vagus?

Answer 5

(normally the usual should move upwards in the midline)

if there is an abnormality involving the vagus, the uvula will deviate AWAY from the side of the lesion

Question 6

Describe the borders of the pharynx.

Answer 6

Base of the skull and the inferior border of the cricoid cartilage

Question 7

What are the three parts of the pharynx and what are their borders?

Answer 7

Nasopharynx – down to the soft palate (pharyngeal isthmus)
Oropharynx – between the soft palate and the epiglottis
Laryngopharynx – between the epiglottis and the cricoid cartilage

Question 8

What happens to the epiglottis when you swallow?

Answer 8

Retroflexion to cover the laryngeal inlet

Question 9

What is the role of the soft palate in swallowing?

Answer 9

It elevates to close off the nasopharynx so that food doesn’t go into the nasal cavity

Question 10

What is the Piriform Fossa and what is its clinical significance?

Answer 10

The piriform fossae are depressions on either side of the laryngeal inlet where food (commonly fish bones) get stuck
has a very sensitive innervation - can become very painful and cause coughing when food becomes lodged here

Question 11

Which muscles aid the passage of a bolus of food down the oesophagus?

Answer 11

Superior, middle and inferior pharyngeal constrictor muscles

Question 12

Which nerves provide sensory innervation of the pharyngeal wall?

Answer 12

Glossopharyngeal and Vagus (pharyngeal plexus)

Question 13

Which nerves provide motor innervation of the pharyngeal constrictor muscles?

Answer 13

Vagus (and a bit of accessory)

Question 14

Describe the changes that occur during swallowing.

Answer 14

• mastication
• 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

Question 15

Name the three salivary glands, describe their secretions and state the nerves that provide secretomotor innervation to them.

Answer 15

Parotid – serous – glossopharyngeal
Submandibular – serous – facial
Sublingual – mucous – facial

Question 16

Which muscle does the parotid duct pierce and where does it open into the buccal cavity?

Answer 16

Buccinator

It opens next to the second upper molar

Question 17

Name the main muscles of the tongue. Which nerve innervates all of this?

Answer 17

Genioglossus, Hyoglossus, Styloglossus
Intrinsic Muscles
These are all innervated by the hypoglossal nerve

Question 18

What other muscle is associated with the tongue but isn’t innervated by the hypoglossal nerve?

Answer 18

Palatoglossus – it is innervated by the vagus

Question 19

What tongue movements do the genioglossus and styloglossus perform?

Answer 19

Genioglossus – protracts the tongue

Styloglossus – retracts and elevates the tongue

Question 20

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?

Answer 20

Towards the side of the lesion because the genioglossus is used in protracting the tongue

Question 21

What movement is palatoglossus responsible for?

Answer 21

Elevates the soft palate and moves the back of the tongue upwards

Question 22

Describe the sensory innervation of the tongue.

Answer 22

Anterior 2/3 sensation – mandibular branch of trigeminal
Anterior 2/3 taste – facial
Posterior 1/3 everything – glossopharyngeal (and vagus)

Question 23

To which structure in the brainstem do the neurons of taste go? It is considered the main taste centre within the brainstem.

Answer 23

Nucleus Solitarius

Question 24

State the origin and insertion of the masseter and the movement that it is responsible for.

Answer 24

Zygomatic Arch
Lateral surface of the ramus of the mandible and the angle of the mandible

Elevates the mandible (allows forced closure of the mouth)

Question 25

State the origin and insertion of temporalis and the movement that it is responsible for.

Answer 25

Temporal Fossa Coronoid Process Elevates and retracts mandible

Question 26

What is the test for the mandibular branch of the trigeminal nerve?

Answer 26

clench your teeth | the masseter muscle will budge and can be palpated at the back of the mandible

Question 27

All of the muscle of mastication are innervated by the _____ nerve, EXCEPT _____

Answer 27

trigeminal buccinator (innervated by the facial nerve) (Buccinator is a muscle of the facial expression.)

Question 28

State the origin and insertion of the medial and lateral pterygoid muscles

Answer 28

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

Question 29

State the movements that the medial and lateral pterygoid muscles are responsible for.

Answer 29

Lateral – Movement – depresses and protracts mandible to open the mouth Medial – Movement – elevates, protracts and lateral movement of mandible for chewing

Question 30

Describe the structure of the temporomandibular joint.

Answer 30

It 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

Question 31

Describe the movements around the temporomandibular joint when opening the mouth.

Answer 31

When opening the mouth slightly there is a hinge action When the mouth is opened further, the head of the mandible glides anteriorly on the articular tubercle of the temporal bone

Question 32

State the eight branches of the external carotid artery.

Answer 32

``` Some Anatomists Like Fucking Over Poor Medical Students ``` ``` (inferior to superior) Superior Thyroid Ascending Pharyngeal Lingual Facial Occipital Posterior Auricular Maxillary Superficial Temporal ```

Question 33

At the level of what anatomical landmark does the common carotid artery bifurcate?

Answer 33

At the level of the laryngeal prominence (C4)

Question 34

Why does the facial artery have a wavy course across the mandible?

Answer 34

If it were taut, then when the mouth is opened the facial artery would rupture

Question 35

Which branch of the external carotid artery gives rise to the middle meningeal artery?

Answer 35

Maxillary

Question 36

Through which foramen does the middle meningeal artery enter the skull?

Answer 36

Foramen Spinosum

Question 37

State the five branches of the facial nerve.

Answer 37

``` Temporal Zygomatic Buccal Mandibular Cervical ``` (tell zainab beauty means confidence)

Question 38

Where does the facial nerve exit the cranial cavity? Where does the facial nerve emerge? Where do the 5 branches emerge?

Answer 38

through the internal acoustic meatus (along with the vestibulocochlear nerve) emerges through the stylomastoid foramen 5 branches emerge from the anterior border of the parotid gland

Question 39

What cranial nerve is the parotid gland innervated by?

Answer 39

CN IX - glossopharyngeal nerve

Question 40

What are the two main branches of the mandibular branch of the trigeminal nerve?

Answer 40

Lingual Nerve | Inferior Alveolar Nerve

Question 41

What are the functions of the lingual and inferior alveolar nerve?

Answer 41

Inferior Alveolar – innervates the lower teeth (this is the one that is stimulated in tooth ache) Lingual – sensation (touch and taste) to the anterior 2/3 of the tongue AND secretomotor to the sublingual and submandibular salivary glands

Question 42

What fibres join the lingual nerve?

Answer 42

Some fibres of the facial nerve via the Chorda Tympani (this is why the lingual nerve is responsible for taste) - this is a branch of the main facial nerve

Question 43

Which cranial nerve provides all sensory innervation of the face?

Answer 43

Trigeminal Nerve

Question 44

Where does the mental nerve stem from? Where does it exit the cranial cavity?

Answer 44

it is a branch of the inferior alveolar nerve (which is a branch of the mandibular) exits via the mental foramen

Question 45

What is Bell’s Palsy and how may it present in a patient?

Answer 45

Facial nerve palsy | Inability to contract muscles of facial expression and altered taste

Question 46

Which nerves innervate the following muscles: a. Temporalis b. Masseter c. Buccinator d. Medial and Lateral Pterygoids e. Pharyngeal Constrictors f. Digastric g. Mylohyoid

Answer 46

``` a. Temporalis Mandibular (trigeminal) b. Masseter Mandibular (trigeminal) c. Buccinator Buccal (facial) d. Medial and Lateral Pterygoids Mandibular (trigeminal) e. Pharyngeal Constrictors Sensory = Glossopharyngeal (IX) + Vagus (X) Motor = Vagus (X) (and a bit of Accessory (XI)) f. Digastric Anterior belly = Mandibular (trigeminal) Posterior belly = Facial g. Mylohyoid Nerve to mylohyoid – branch of inferior alveolar nerve (a branch of the mandibular) ```

Question 47

What are the branches coming off the inferior alveolar nerve?

Answer 47

Mental nerve – terminal branch (provides sensation to the front of the chin) Nerve to mylohyoid

Question 48

What are the full numbers in a typical permanent set of teeth?

Answer 48

32 16 upper and 16 lower 8 incisors, 4 canines, 8 premolars and 12 molars (including 4 wisdom teeth)

Question 49

How many deciduous (baby) teeth are there?

Answer 49

20 | in each quadrant: 2 incisors, I canine and 2 molars

Question 50

Which teeth are missing in the deciduous set compared to the adult set?

Answer 50

No premolars or wisdom teeth

Question 51

When do the first deciduous teeth erupt?

Answer 51

Around 6 months

Question 52

When is the deciduous set usually complete?

Answer 52

Around 20-24 months

Question 53

Why are the tonsils clinically important?

Answer 53

They are areas of lymphoid tissue so they can get infected and inflamed

Question 54

What is the simplest test of the glossopharyngeal nerve?

Answer 54

Test the patient’s gag reflex by sticking something down their throat

Question 55

How is the hypoglossal nerve tested?

Answer 55

Ask the patient to stick their tongue out

Question 56

How is the trigeminal nerve tested?

Answer 56

Sensory – touch the patient around the jawline, on the cheek and on the forehead (to test the three divisions) Motor – ask the patient to clench their teeth and try to palpate the bulge of the masseter and temporalis

Question 57

How is the facial nerve tested?

Answer 57

Ask the patient to crease up their forehead by raising their eyebrows Ask the patient to keep their eyes closed against resistance

Question 58

What is the mnemonic for branches of the external carotid artery?

Answer 58

``` Some Anatomists Like Freaking Out Poor Medical Students ```