Week 1- anatomy

Question 1

Describe the intracranial course of the trigeminal nerve

Answer 1

Attaches to the pons

Runs inferior to the tentorium cerebellum between the posterior and middle cranial fossa.

Question 2

Which foramen do the trigeminal nerve branches exit the cranium by?

Answer 2

CN V1- superior orbital fissure
CN V2- foramen rotundum
CN V3- foramen ovale

Question 3

Where does the first branch of the trigeminal nerve supply (sensory)? Include deep structures

Answer 3

It supplies the forehead, upper eyelid down to the tip of the nose.
Deep structures include all the paranasal sinus’s (minus maxillary), the upper anterior nasal cavity, the bones and soft tissues of the orbit and the anterior and posterior cranial fossa.

Question 4

Where does the second branch of the trigeminal nerve supply (sensory)? Include deep structures?

Answer 4

The lower eyelid to the mid cheek and upper lip.
Deep structures- lower posterior nasal cavity, maxilla and maxillary sinus, floor of the nasal cavity and palate, maxillary teeth and associated soft tissue (gingival)

Question 5

Where does the third branch of the trigeminal nerve supply (sensory)? Include deep structures

Answer 5

Supplies from the mid cheek to the chin. Does not supply the angle of the mandible.
Deep structures are the mandibular teeth, anterior 2/3rds of the tongue, floor of the mouth, buccal mucosa and middle cranial fossa.

Question 6

What muscles does the motor division of the trigeminal nerve supply?

Answer 6

Muscles of mastication

Question 7

Name the three jaw closing muscles and their attachments

Answer 7

Masseter- from the angle of mandible to the zygomatic arch
temporalis- coronoid process of mandible- lateral aspect of neurocranium
Medial pterygoid- angle of mandible to pterygoid plate of sphenoid bone

Question 8

How would you clinically test the sensory division of the trigeminal nerve?

Answer 8

Ask the patient to close their eyes and touch a cotton bud to the areas of the face supplied by each division. Ask the patient to say when they can feel anything. Compare sides.

Question 9

How would you clinically test the motor division of the trigeminal nerve?

Answer 9

Test the strength of the jaw closing muscles (specifically masseter and temporalis) by asking the patient to clench their teeth
Ask the patient to open their jaw against resistance (lateral pterygoid)

Question 10

Describe the path of the facial nerve from intracranial to extracranial

Answer 10

Intracranially- originates at the pons-medullary junction. Travels straight into the internal acoustic meatus in the posterior cranial fossa. From here it travels through the facial canal (and gives off a branch to the chorda tympani) and then through the stylomastoid foramen.
Most motor fibres pass into the parotid gland and then exit via one of the 5 branches.

Question 11

What does the chorda tympani branch supply and which nerve does it join?

Answer 11

The chorda tympani branch supplies taste to the anterior 2/3rds of the tongue and parasympathetic supply to the salivary gland. It joins the lingual nerve (a branch of CN V3)

Question 12

What does the facial nerve supply (not the chorda tympani branch)?

Answer 12

The muscles of facial expression.

Question 13

Name the muscles of facial expression

Answer 13

Frontalis, orbicularis oculi, orbicularis oris, elevator of the lips

Question 14

How would you clinically test the facial nerve?

Answer 14

Ask the patient to frown, close eyes tightly, puff out cheeks and smile.

Question 15

Describe the intracranial and extracranial course of the glossopharyngeal nerve?

Answer 15

Originates in the superior medulla. Passes straight into the jugular foramen. Extracranial axons go down to the pharynx and tongue.

Question 16

What modalities of axons does the glossopharyngeal nerve contain?

Answer 16

General sensory
Special sensory
Somatic motor
Parasympathetic 
Visceral afferent

Question 17

Describe the general sensory supply of CN IX

Answer 17

Supplies the posterior 1/3rd of the tongue, most of the nasopharynx, all of the oropharynx and some of the laryngopharynx. Also supplies the palatine tonsil, Eustachian tube and middle ear.

Question 18

Describe the special sensory supply of CN IX?

Answer 18

Special sensory to the posterior 1/3rd of the tongue. Via vallate papillae.

Question 19

Describe the somatic motor supply of CN IX?

Answer 19

To one of the longitudinal muscles of the pharynx

Question 20

Describe the parasympathetic supply of CN IX?

Answer 20

To the parotid gland

Question 21

Describe the visceral afferent supply of CN IX?

Answer 21

To the carotid baroreceptors and chemoreceptors.

Question 22

Describe the course of the vagus nerve intracranially to extracranially

Answer 22

Connects from the medulla just inferior to the CN IX. Goes directly towards jugular foramen.

Question 23

Where does the vagus nerve sit in the neck?

Answer 23

Within the carotid sheath

Question 24

What other structures are in the carotid sheath?

Answer 24

Deep cervical lymph nodes
Common carotid artery
Internal jugular vein

Question 25

In the chest, where does the vagus nerve pass?

Answer 25

On the right- travels on the lateral aspect of the trachea
On the left- on the lateral aspect of the aortic arch
They then pass onto the posterior lung root and then onto the oesophagus. They pass through the diaphragm with the oesophagus.

Question 26

Where in the abdomen does the vagus nerve supply?

Answer 26

-spleen, pancreas, stomach, foregut, midgut and renal.

Question 27

How would you clinically test the vagus nerve?

Answer 27

Ask patent to say ‘ah’. Uvula should stay in the midline. If there is unilateral pathology- the uvula will point away from the side with it.
Ask patient to swallow water- spluttering suggest issues with larynx
Listen to speech- hoarseness may be due to an issue with the muscles
Ask patient to cough

Question 28

Describe the path of the spinal accessory nerve?

Answer 28

Originates from the anterior rootlets of the cervical spinal nerves. Ascends through the foramen magnum and heads towards the jugular foramen. Passes down through the jugular foramen and supplies the sternocleidomastoid. Then passes through the posterior triangle to supply the trapezius muscle.

Question 29

How would you clinically test the spinal accessory nerve?

Answer 29

Ask the patient to shrug their shoulders.

Ask them to turn to look up at the opposite side.

Question 30

Describe the course of the hypoglossal nerve intracranially and extracranially?

Answer 30

Originates from several rootlets that attach to the lateral pyramids of the medulla.
Passes anteriorly towards the hypoglossal canal.
Descends in the neck lateral to the carotid sheath. At the level of the hyoid bone passes anteriorly towards the lateral aspect of the tongue.

Question 31

What does the hypoglossal nerve supply?

Answer 31

Most of the tongue muscles.

Question 32

How would you clinically test the hypoglossal nerve?

Answer 32

Ask patient to stick their tongue out. If there isn’t pathology- the tip of the tongue will remain in the midline. if there is pathology- the tongue will point towards the injured side.

Question 33

Damage to a spinal nerve may cause these sensory symptoms (use both medical and laymans terms)

Answer 33

Paraesthesia (pins and needles)
Neuralgia- pain
Anaesthesia (numbness)
Sensitivity (hyperaesthesia)
Temperature perceptions
Loss of co-ordination/balance/clumsiness

Question 34

Damage to a spinal nerve may cause these motor symptoms

Answer 34

Muscle stiffness
Muscle tightness or spasm (cramp)
Loss of muscle tone (hypotonia)
Muscle weakness
Loss of co-ordination

Question 35

How would you go about testing the sensory aspect of spinal nerves?

Answer 35

Using dermatomes

Question 36

How would you go about testing the motor aspect of spinal nerves?

Answer 36

Using myotomes

Question 37

How would you test the motor and sensory aspect of spinal nerves simultaneously?

Answer 37

Using spinal cord reflexes.