Cranial nerves

Question 1

Cranial Nerve XII: effects of injury

Answer 1

Tongue deviates to one side or can’t protrude

Question 2

Cranial Nerve XI: effects of injury

Answer 2

Trapezius paralysis (shoulder drooping, difficulty raising arm above horizontal plane). Can happen during lymph node biopsies. Or, sternocleidomastoid paralysis (difficulty turning head).

Question 3

Cranial Nerve X: effects of injury

Answer 3

The recurrent laryngeal nerve supplies visceromotor innervation to the only muscle abducting the vocal cords, so hoarseness can happen. Bilateral injury can cause respiratory distress.

Question 4

Cranial Nerve VIII: effects of injury

Answer 4

Vestibular part: dizziness

Cochlear part: Hearing loss

Question 5

Cranial Nerve VII: effects of injury

Answer 5

Peripheral facial nerve injury: paralysis of muscles of facial expression on affected side. Also, disturbances of taste, lacrimation, salivation, etc.

Question 6

Cranial Nerve V: effects of injury

Answer 6

Sensory loss, herpes zoster opthalmicus (eye pain, facial rash), trigeminal neuralgia (intense facial pain)

Question 7

Cranial Nerve VI: effects of injury

Answer 7

Diplopia: Affected eye deviates superiorly

Question 8

Cranial Nerve IV: effects of injury

Answer 8

diplopia: affected eye is higher and deviated medially

Question 9

Cranial Nerve III: effects of injury

Answer 9

Paralysis of intraocular muscles, drooping of eyelid, diplopia, pupil dilation

Question 10

Cranial Nerve I: ABC

Answer 10

Olfactory
A: Sensory
B: Smell
C: Receptors in nose, pass through the cribriform plate, olfactory bulb and olfactory tract in forebrain

Question 11

Cranial Nerve II: ABC

Answer 11

Optic
A: Sensory
B: Vision
C: The optic nerve passes through the optic canal and to the optic chasm. The optic tracts then lead to lateral geniculate bodies in the occipital lobe.

Question 12

Cranial Nerve III: ABC

Answer 12

Occulomotor
A: Motor
B: Powers levitator palpebrae, inferior oblique, medial rectus, and superior and inferior rectus muscles
C: In the midbrain; it exits the skull through the superior orbital fissure.

Question 13

Cranial Nerve IV: ABC

Answer 13

Trochlear
A: Motor
B: Motor to the superior oblique muscle of the eye
C: Longest course. It passes through the superior orbital fissure.

Question 14

Cranial Nerve V: ABC

Answer 14

Trigeminal
A: BOTH
B: Ophthalmic (sensory for facial skin, nasopharyngeal mucosa, anterior two thirds of the tongue, passes through superior orbital fissure)
Maxillary (sensory to lower eyelid, superior lip, gums, teethe, cheek, part of nose, palate, and part of throat; exits through foramen rotundum)
Mandibular (both: sensory to inferior gums, teeth, lips, part of palate, and part of tongue; motor to muscles of mastication; exits through foramen ovale)

Question 15

Cranial VI: ABC

Answer 15

Abducens
A: motor
B: Motor to lateral rectus muscle of the eye
C: passes through superior orbital fissure

Question 16

Cranial VII: ABC

Answer 16

Facial
A: Both
B: Has 5 branches: Temporal, zygomatic, buccal, mandibular, cervical
(Sensory: taste receptors on anterior two- thirds of tongue; Motor: muscles of facial expression, lacrimal gland, submandibular and sublingual salivary glands)
C: is found near MO, internal acoustic meatus, stylomastoid foramen, parotid gland

Question 17

Cranial VIII: ABC

Answer 17

Vestibulocochlear
A: Sensory
B: Hearing and equilibrium
C: passes through internal acoustic meatus

Question 18

Cranial IX: ABC

Answer 18

Glossopharyngeal
A: Both
B: Swallowing, salivation, taste
C: Passes through jugular foramen (medulla, posterior throat, back of tongue, parotids)

Question 19

Cranial X: ABC

Answer 19

Vagus
A: BOTH
B: Sensory (throat, ear, diaphragm, visceral organs in thoracic and abdominopelvic cavities)
Motor: palatal and throat muscle and visceral organs in thorax and abdomen
C: jugular foramen

Question 20

Cranial XI: ABC

Answer 20

Spinal accessory nerve
A: Motor
B: internal and external parts
Internal: skeletal muscles of palate, through and larynx (with vagus)
External: Sternocleidomastoid and trapezius muscles)
C: passes through the jugular foramen

Question 21

Cranial XII: ABC

Answer 21

Hypoglossal
A: Motor
B: Motor to tongue muscles
C: Passes through the hypoglossal canal

Question 22

Tumor on the optic chasm translates into?

Answer 22

tunnel vision