Cranial Nerves Fundamentals

Question 1

Cranial nerve sensory ganglia?

Answer 1

TGIS9+10: Trigeminal (CN V), Geniculate (CN VII), Inferior and Superior ganglia (of CN IX, X)

Question 2

Cranial nerve motor (i.e. parasympathetic) ganglia?

Answer 2

COPS: Ciliary (CN III), Otic (CN IX), Pterygopalatine (CN VII), Submandibular (CN VII) and Intramural (CN X)

Question 3

Nerves traversing the jugular foramen?

Answer 3

CN IX, X, XI

Question 4

Nerves traversing the supraorbital fissure?

Answer 4

CN III, CN IV, V1 [opthalmic]

Question 5

Nerves traversing the cavernous sinus?

Answer 5

CN III, CN IV, V1 [opthalmic] and V2 [maxillary] + internal carotid plexus [sympathetic]

Question 6

Nerve traversing the foramen rotundum?

Answer 6

CN V2 [maxillary]

Question 7

Nerve traversing the foramen ovale?

Answer 7

CN V3 [mandibular]

Question 8

Nerves traversing the foramen magnum?

Answer 8

CN XI + sympathetic plexus on vertebral artery

Question 9

Nerves traversing the internal auditory meatus?

Answer 9

CN VII, VIII

Question 10

Nerve traversing the stylomastoid foramen?

Answer 10

CN VII

Question 11

Muscles innervated by CN V?

Answer 11

Temporalis, masseter, medial and lateral pterygoid, anterior belly of digastric muscle, tensor tympani, tensor veli palatini, mylohyoid

Question 12

Motor signs with CN V injury?

Answer 12

Asymmetric jaw closing (deviates to good side), atrophy of temporalis, maseter

Question 13

GSA innervation to upper eyelid?

Answer 13

CN V: opthalmic division

Question 14

GSA innervation to lower eyelid?

Answer 14

CN V: maxillary divison

Question 15

GSA innervation to tip of nose?

Answer 15

CN V: opthalmic division

Question 16

GSA innervation to upper lip?

Answer 16

CN V: maxillary divison

Question 17

GSA innervation to lower lip?

Answer 17

CN V: mandibular division

Question 18

GSA innervation to anterior 2/3 of tongue?

Answer 18

CN V: mandibular division

Question 19

Muscles innervated by CN VII?

Answer 19

Muscles of facial expression, posterior belly of digastric, stylohyoid, stapedius

Question 20

Motor signs with CN VII injury?

Answer 20

Bell’s palsy: complete facial paralysis: patient can’t wrinkle forehead, close eye tightly or smile on affected side

Question 21

Muscle innervated by CN IX?

Answer 21

Stylopharyngeus

Question 22

Motor signs with CN IX injury?

Answer 22

Dysphagia

Question 23

Skeletal muscles innervated by CN X?

Answer 23

Levator veli palatini palatoglossus, all pharyngeal (except stylopharyngeus), laryngeal + esophagus

Question 24

Skeletal muscle innervated by recurrent laryngeal n?

Answer 24

All laryngeal muscles except cricothyroid

Question 25

Skeletal muscle innervated by external laryngeal n?

Answer 25

Cricothyroid (mabes some constrictor m.)

Question 26

Motor signs with CN X injury?

Answer 26

Dysphagia, hoarseness, sagging palate, uvula deviates to opposite side

Question 27

Muscles innervated by CN XI?

Answer 27

Trapezius, SCM

Question 28

Motor signs with injury to CN XI?

Answer 28

Weakness shrugging shoulder, cannot abduct humerus beyond 90*, weakness turning head to opposite side

Question 29

Muscles innervated by CN XII?

Answer 29

Genioglossus, hyoglossus, styloglossus, intrinsic tongue muscles

Question 30

Motor signs with CN XII injury?

Answer 30

Fasciculations, atrophy, on attempted protrustion the tongue deviates to side of the lesion

Question 31

Skin innervated by CN VII, IX and X?

Answer 31

Small area around ear

Question 32

What is Ramsay Hunt syndrome?

Answer 32

Herpes infection in the geniculate ganglion

Question 33

Signs of Ramsay Hunt syndrome?

Answer 33

IL facial paralysis, hyperacusis, loss of taste, herpes vesicles on external ear, canal

Question 34

Viscera innervated by CN III?

Answer 34

Sphincter pupillae, ciliary muscle

Question 35

Viscera innervated by CN VII?

Answer 35

Mucosa of nasal cavity, oral cavity, lacrimal, submandibular, sublingual glands

Question 36

Viscera innervated by CN IX?

Answer 36

Parotid gland, mucosa of middle ear, mucosa of oropharynx

Question 37

Viscera innervated by CN X?

Answer 37

Muscosa of larynx, pharynx, all viscera of foregut and midgut

Question 38

CN and ganglion for taste at the anterior 2/3s of tongue?

Answer 38

CN VII & genticulate ganglion

Question 39

CN and ganglion for general sensory innervation to anterior 2/3 of tongue?

Answer 39

CN V & trigeminal

Question 40

CN and ganglion for taste at the posterior 1/3 of the tongue?

Answer 40

CN IX & inferior ganglion of IX

Question 41

Signs of Bell’s palsy?

Answer 41

Patient cannot wrinkle their forehead, close eye tightly, wrinkle nose, smile

Question 42

Signs of CN VII injury at the internal auditory meatus?

Answer 42

IL complete facial paralysis, dry eye, dry mouth, hyperacusis, decreased taste on anterior 2/3 of tongue

Question 43

Signs of vestibular Schwannoma?

Answer 43

Headache, papilledema, IL complete facial paralysis, dry eye, dry mouth, decreased taste on anterior 2/3 of tongue, hearing loss/tinnitus

Question 44

Signs of CN VII injury in facial canal?

Answer 44

IL complete facial paralysis; dry mouth, decreased taste on anterior 2/3 of tongue

Question 45

Signs of CN VII injury at the stylomastoid foramen?

Answer 45

IL complete facial paralysis

Question 46

Signs of injury to chorda tympani?

Answer 46

Loss of taste on anterior 2/3 of tongue, dry mouth

Question 47

Signs and symptoms of injury to hypoglossal nerve?

Answer 47

IL, tongue paralysis; on protrusion tongue points towards leison

Question 48

Signs and symptoms of injury to the motor root of the trigeminal nerve?

Answer 48

IL, paralysis of muscles of mastification, weakness in jaw closing, protusion, dry mouth [parotid]

Question 49

Signs and symptoms of injury to the tympanic nerve (CN IX)?

Answer 49

Dry mouth [parotid]

Question 50

Nerves for corneal reflex? [afferent efferent]

Answer 50

CN V, CN VII

Question 51

Nerves for pupillary light reflex? [afferent efferent]

Answer 51

CN II, CN III

Question 52

Nerves for jaw jerk? [afferent efferent]

Answer 52

CN V, CN V

Question 53

Nerves for cough reflex? [afferent efferent]

Answer 53

CN X, CN X [+ C3-T12 for diaphragm and intercostals]

Question 54

Nerves for gag reflex? [afferent efferent]

Answer 54

CN IX, CN X

Question 55

Nerve most likely affected with aneursym of ICA in cavernous sinus

Answer 55

CN VI