Cranial Nerves

Question 1

cranial nerves (V, VII, IX, and X) cell bodies location

Answer 1

cranial sensory ganglia

just outside brain

Question 2

Corticobulbar (Corticonuclear) Innervation of Cranial Nerve Nuclei

Answer 2

upper motor neuron innervation of lower motor neurons

Muscles of mastication (CN V)

Muscles of facial expression (CN VII) - (partially bilateral**)

Palate, pharynx, and larynx (CN X)

Tongue (CN XII)

Sternocleidomastoid and trapezius muscles (CN XI)

Question 3

alar plate innervation

Answer 3

sensory

Question 4

basal plate innervation

Answer 4

motor

Question 5

CN I

Answer 5

Olfactory Nerve

sensory

sense of smell

Question 6

CN I damage

Answer 6

Results in anosmia (loss of olfactory sensation)

Question 7

CN II

Answer 7

Optic nerve

sensory

impulse for vision

Question 8

CN II damage

Answer 8

papilledema

optic atrophy

Question 9

CN III nerves

Answer 9

Oculomotor Nerve

eye movement*

Somatic motor (inferior oblique and superior, inferior, and medial rectus muscles) - all except SO & LR

Question 10

Oculomotor (III) nerves damage

Answer 10

*** eye turned out and down

in oculomotor nerve paralysis, eye cannot be moved up, down, or inward

At rest, eye rotates laterally (external strabismus)

Question 11

CN IV nerves

Answer 11

Trochlear Nerve

• motor: superior oblique muscle (in eye)

Question 12

Trochlear (IV) nerves damage

Answer 12

double vision and impairs ability to rotate eye inferolaterally

Question 13

CN V nerves

Answer 13

Trigeminal Nerve

• sensory of face
• three divisions: ophthalmic, maxillary, and mandibular

Question 14

Trigeminal (V) nerves damage

Answer 14

• ipsilateral facial sensory loss
• Trigeminal neuralgia (TN) is considered to be one of the most painful afflictions known to medical practice

feels like an electric shock or stabbing but may feel like burning

Question 15

CN VI nerves

Answer 15

Abducens Nerves

*primarily motor: lateral rectus muscle (in eye)

Question 16

Abducens (VI) nerves damage

Answer 16

*ipsilateral eye abduction weakness

Abducens nerve paralysis, eye cannot be moved laterally

At rest, eyeball rotates medially (internal strabismus)*

Question 17

CN VII nerves

Answer 17

Facial Nerve

mixed innervation

Five major branches: Temporal, Zygomatic, Buccal, Mandibular, and Cervical

Question 18

Facial (VII) nerves functions

Answer 18

• muscles of facial expression
• taste buds of anterior two-thirds of tongue
• damage leads to ipsilateral facial weakness/drop
• Bells Palsy

Question 19

UMN vs LMN facial weakness

Answer 19

UMN:
can see forehead wrinkles (Supranuclear lesion)

LMN:
Entire side of face is paralyzed (Bells Palsy)

Question 20

Bell’s palsy

Answer 20

paralysis or severe weakness of the nerve that controls the facial muscles on the side of the face - the facial nerve or seventh cranial nerve

** NO FOREHEAD WRINKLES

Question 21

CN VIII nerves

Answer 21

Vestibulocochlear Nerves

sensory

*hearing and equilibrium

Question 22

Vestibulocochlear (VIII) nerves damage

Answer 22

*ipsilateral deafness

Lesions of cochlear nerve result in central, or nerve, deafness

Damage to vestibular division produces dizziness, rapid involuntary eye movements, loss of balance, nausea, and vomiting

Question 23

CN IX nerves

Answer 23

Glossophangeal Nerves

mixed innervation

*taste of posterior 1/3 of tongue

Question 24

Glossopharyngeal (IX) nerves damage

Answer 24

ipsilateral pharyngeal sensory loss

*impaired swallowing and taste

Question 25

CN X nerves

Answer 25

Vagus Nerve

mixed innervation

• motor: heart, lungs, bronchi, GIT
  sensory: heart, lungs, bronchi, trachea, *larynx, *pharynx, GIT, external ear
• ONLY CN THAT TRAVELS BELOW BRAINSTEM

Question 26

Vagus (X) nerves damage

Answer 26

ipsilateral palatal weakness

hoarseness or loss of voice

*difficulty swallowing and impaired digestive system motility

Question 27

CN XI nerves

Answer 27

Accessory Nerves

motor

*trapezius and sternocleidomastoid muscles

Question 28

Accessory (XI) nerves damage

Answer 28

*ipsilateral shoulder weakness

causes head to turn toward injury side as result of sternocleidomastoid muscle paralysis

Shrugging the shoulder (role of trapezius muscle) becomes difficult

Question 29

CN XII nerves

Answer 29

Hypoglossal Nerves

primarily motor

*movement of tongue

Question 30

Hypoglossal (XII) nerves damage

Answer 30

*ipsilateral weakness of tongue

** If only one side is affected, tongue deviates (points) toward affected side; eventually paralyzed side begins to atrophy

If both nerves are impaired, the person cannot protrude tongue

causes difficulties in speech and swallowing