Clinical anatomy of cranial nerves

Question 1

What runs in the cribriform plate of the ethmoid bone?

Answer 1

Olfactory nerve

Question 2

What is the contents of the optic canal of the sphenoid bone?

Answer 2

Optic nerve and the ophthalmic artery

Question 3

In what bone is the superior orbital fissure?

Answer 3

Sphenoid

Question 4

What runs in the SOF?

Answer 4

Lacrimal nerve
CN V1 
Superior ophthalmic vein 
CN 4
CN 3 
CN 6 
Inferior ophthalmic vein

Question 5

What runs in the foramen rotundum?

Answer 5

Maxillary nerve

Question 6

What runs in the foramen ovale?

Answer 6

Mandibular nerve

Question 7

What runs in the internal acoustic meatus?

Answer 7

Facial nerve
Vestibulocochlear nerve
Vestibular ganglion
Labyrinthe artery

Question 8

What runs in the jugular foramen?

Answer 8

Inferior petrosal sinus
Glossopharyngeal nerve, vagus nerve and spinal accessory nerve
Sigmoid sinus

Question 9

In what bone is the internal acoustic meatus?

Answer 9

Petrous part of temporal bone

Question 10

In what bone is the hypoglossal canal?

Answer 10

Occipital bone

Question 11

What runs in the hypoglossal canal?

Answer 11

Hypoglossal nerve

Question 12

What runs in the foramen magnum?

Answer 12

Medulla
Meninges
Vertebral arteries
Anterior and posterior spinal arteries
Dural veins

Question 13

What runs in the foramen spinosum?

Answer 13

Middle meningeal artery

Question 14

Where will the optic nerve connect with the CNS?

Answer 14

Diencephalon at the lateral geniculate nucleus where it will then radiate to the visual cortex at the occipital lobe

Question 15

How can the optic nerve be tested?

Answer 15

Acuity - snellen
Colour - ishihara
Fields
Reflexes
Fundoscopy

Question 16

Where does the oculomotor nerve originate?

Answer 16

Midbrain

Question 17

What are the contents of the cavernous sinus?

Answer 17

Oculomotor nerve
Trochlear nerve
Ophthalmic branch of trigeminal nerve
Maxillary branch of trigeminal nerve
Internal carotid artery
Abducens nerve

Question 18

Where does the trochlear nerve originate?

Answer 18

Midbrain

Question 19

Where does the abducens nerve originate?

Answer 19

Pontomedullary junction

Question 20

How are CN 3,4 and 6 tested?

Answer 20

H test - eye movements

Question 21

Where does the vestibulocochlear nerve originate?

Answer 21

Pontomedullary junction

Question 22

How is the vestibulocochlear nerve tested?

Answer 22

Rinne

Weber

Question 23

Describe rinne and weber testing?

Answer 23

Rinne - hold infront of ear and then on mastoid. In conducive hearing loss, you will hear better when on mastoid whereas in sensorineural you will hear better in air
Weber - hold tuning fork on head - sensorineural it will lateralise to normal ear but in conduction it will go towards affected ear

Question 24

Where does the spinal accessory nerve originate on the CNS?

Answer 24

Cervical spinal cord - top 4 segments

Question 25

How is the spinal accessory nerve tested?

Answer 25

Shug shoulders = trapezius | Turn head to flex neck and turn head towards opposite side

Question 26

Where does the hypoglossal nerve connect with the CNS?

Answer 26

Via many rootlets lateral to the pyramids of the medulla oblongata

Question 27

Where will the hypoglossal canal descend?

Answer 27

Lateral to the carotid sheath | At level of hyoid, tuns anteriorly towards lateral aspect of tongue

Question 28

What is the medullary olive?

Answer 28

Inferior olive - cerebellar system | Superior orlive - pons and part of the auditory system, aiding the perception of sound

Question 29

What innervates the palatoglossus muscle?

Answer 29

Vagus nerve

Question 30

How is the hypoglossal nerve tested?

Answer 30

Stick tongue straight out If there is unilateral pathology - the tongue tip will point towards the injured nerve The Tongue tells the Truth

Question 31

Which division of the trigeminal nerve provides sensory and motor innervation?

Answer 31

Only mandibular division

Question 32

What part of the brain does the trigeminal nerve come off?

Answer 32

Pons

Question 33

Where does the trigeminal nerve run in the brain?

Answer 33

Inferior to edge of tentorium cerebelli between post and middle cranial fossa

Question 34

What type of neurones will the trigeminal sensory have?

Answer 34

Pseudounipolar = SENSORY NEURONES

Question 35

What is the sensory distribution of CN V1?

Answer 35

Upper eyelid Cornea (corneal reflex) Conjunctiva Skin of root/bridge/tip of nose

Question 36

What is the sensory distribution of CN v2?

Answer 36

Skin of lower eyelid Skin over maxilla Skin over ala of nose Skin of upper lip

Question 37

What is the sensory distribution of CN V3?

Answer 37

Skin over mandible and TMJ

Question 38

What supplies the angle of the mandible?

Answer 38

Greater auricular nerve; C2,3

Question 39

What is the deep sensory territory of V1?

Answer 39

Bones and soft tissues of orbit Upper anterior nasal cavity Paranasal sinuses except the maxillary sinus Anterior and posterior cranial fossa

Question 40

What is the deep sensory territory of V2?

Answer 40

Lower posterior nasal cavity Maxilla and maxillary sinus Floor of nasal cavity/ palate Maxillary teeth and assoc soft tissues

Question 41

What is the deep sensory territory of V3?

Answer 41

``` Middle cranial fossa Mandible Anterior 2/3rds of tongue Floor of mouth Buccal mucosa Mandibular teeth ```

Question 42

What is the CN V3 motor supply?

Answer 42

``` Masseter Temporalis Medial Pteygoid Lateral pteygoid Tensor veli palatini Tensor tympani ```

Question 43

Where does the facial nerve connect to the CNS?

Answer 43

Pontomedullary junction

Question 44

What is the course of somatic motor facial nerve axons?

Answer 44

Pass through internal acoustic meatus and then through the stylomastoid foramen Pass into the parotid gland to then supply muscles of facial expression

Question 45

What is the action of the chorda tympani?

Answer 45

Taste buds to anterior 2/3rds of tongue | Parasymp to submandibular and sublingual glands

Question 46

What muscle in the inner ear does the facial nerve supply?

Answer 46

Stapedius muscle

Question 47

What is the function of the lingual nerve?

Answer 47

V3 to supply general sensation to the anterior 2/3rds of the tongue

Question 48

What are the muscles of facial expression?

Answer 48

Frontalis Orbicularis oris Elevators of lips Orbicularis oculi

Question 49

Where does the glossopharyngeal nerve originate on the CNS?

Answer 49

Medulla oblongata

Question 50

What is the general sensory actions of the glossopharyngeal nerve?

Answer 50

``` Posterior 1/3rd of tongue Mucosa of most of nasopharynx and oropharynx Mucosa of some of laryngopharynx Palatine tonsil Eustachian tube Middle ear cavity ```

Question 51

What is the special sensory action of the glossopharyngeal nerve?

Answer 51

Vallate papillae on post 1/3rd of tongue

Question 52

What is the parasymp action of the glossopharyngeal nerve?

Answer 52

Parotid gland

Question 53

What are the visceral afferent actions of the glossopharyngeal nerve?

Answer 53

Carotid sinus Baroreceptors Carotid body chemoreceptors

Question 54

What is the somatic motor action of the glossopharyngeal nerve?

Answer 54

Stylopharyngeus

Question 55

Where does the vagus nerve connect with the CNS?

Answer 55

Medulla oblongata

Question 56

Where will the vagus nerve run within the neck?

Answer 56

Within the carotid sheath | Posterior to and between the common carotid artery and internal jugular vein

Question 57

Describe the differences between the left and right recurrent laryngeal nerves?

Answer 57

Left hooks under arch of aorta | Right hooks under right subclavian