Cranial Nerves

Question 1

Cranial Nerve I

Answer 1

Olfactory Nerve responsible for the special sensory innervation of Smell

Really a collection of axons, not a singular nerve

Question 2

Which nerve is not a distinct and identifiable nerve like the others?

Answer 2

Cranial Nerve I which is a collection of all of the axons that sense smell

Question 3

Cranial Nerve II

Answer 3

Optic Nerve responsible for vision

Collection of retinal axons that sense light and cross over at OPTIC CHIASM near Sella Turcica (bony encasement of Pituitary Gland)

Question 4

What notable structure is close to the Optic Chiasm? What effect would a tumor have?

Answer 4

Cranial Nerve II crosses over at the Optic Chiasm which is in very close proximity to the Pituitary Gland

2. A Pituitary Gland tumor could result in Bi-Temporal Hemianopsia (tunnel vision)

Question 5

CN III

Answer 5

Oculomotor Nerve responsible for most of extrinsic eye muscles for movement and parasympathetic input to the pupil

“Focuses the pupils for reading on the toilet”

Question 6

CN IV

Answer 6

Trochlear Nerve responsible for looking OUT and DOWN via the Superior Oblique Muscle

Question 7

CN VI

Answer 7

Abducens Nerve responsible for eye aBduction (looking away from midline) via the Lateral Rectus Muscle

Question 8

Which Cranial Nerves control extrinsic eye movement?

Answer 8

CN III
CN IV
CN VI

Question 9

Which Cranial Nerve controls both intrinsic and extrinsic eye muscles?

Answer 9

CN III (Oculomotor)

Question 10

CN VII

Answer 10

Facial Nerve that is responsible for Facial Expression, most Parasympathetic innervation of glands of the face, and special sensory (taste) for anterior 2/3 of tongue

Question 11

What gland is not innervated by CN VII? Why is it still significant?

Answer 11

Parotid Gland is NOT innervated by CN VII (Facial Nerve) BUT it is embedded in the Parotid and forms the Parotid Plexus to innervate Extracranial muscles for facial expression

Question 12

What are the Intracranial Branches of CN VII?

Answer 12

1. Greater Petrosal (parasympathetic innervation of glands on top side of the face through Pterygopalatine Ganglion)
2. Chorda Tympani Nerve (special sensory innervation for Ant 2/3 tongue and parasympathetic innervation of glands on lower side of face through the Submandibular Ganglion)

Question 13

What are the Extracranial Branches of CN VII?

Answer 13

“To Zanzibar by Motor Car”

1. Temporal
2. Zygomatic
3. Buccal
4. Marginal Mandibular
5. Cervical

Question 14

Which condition results in total paralysis of one side of the face?

A. Bell’s Palsy
B. Stroke

Answer 14

Bell’s Palsy results in total paralysis of one side of the face due to problem with CN VII before it ever reaches the face

Stroke has lower paralysis due to Ipsilateral (same side) and Contralateral (opposite side) innervation

Question 15

CN VIII

Answer 15

Vestibulocochlear Nerve with 2 components responsible for Balance (Vestibular Nerve) and Hearing (Cochlear Nerve)

Question 16

CN IX

Answer 16

Glossopharyngeal Nerve provides:

1. General and Special Sensory Innervation of Tongue
2. Visceral Sensory Innervation of Carotid Baroreceptors and Chemoreceptors
3. Visceral Motor Innervation to Parotid Gland

Question 17

CN X

Answer 17

Vagus Nerve provides:

1. General Sensory from Laryngopharynx and Larynx
2. Visceral Sensory from Thoracic and Abdominal organs and chemo/baroreceptors of aortic arch and body
3. Parasympathetic Motor to smooth muscles of thorax, throat glands, and abdomen (foregut and midgut)
4. Somatic Motor to Palatoglossus (Extrinsic Tongue), soft palate, pharynx, and larynx

Question 18

CN XI

Answer 18

NOT REALLY A CRANIAL NERVE

Spinal Accessory Nerve that provides Somatic Motor innervation to Trapezius and Sternocleidomastoid

Question 19

CN XII

Answer 19

Hypoglossal Nerve provides somatic motor innervation to Intrinsic and most of Extrinsic (besides Palatoglossus) Tongue Muscles

Question 20

Name Cranial Nerves I-XII

Answer 20

Old (Olfactory)
Ops (Optic)
Occasionally (Oculomotor)
Troll (Trochlear)
Tristan Thompson (Trigeminal)
About (Abducens)
Failing (Facial)
Versus (Vestibulocochlear)
Green's (Glossopharyngeal)
Vague (Vagus)
Ass (Accessory)
Hype (Hypoglossal)

Question 21

Cranial Nerve Functional information mnemonic

Answer 21

Some (Sensory)
Say (Sensory)
Marry (Motor)
Money (Motor)
But (Both: Sensory and Motor)
My (Motor)
Brother (Both: Sensory and Motor)
Says (Sensory)
Big (Both: Sensory and Motor)
Brains (Both: Sensory and Motor)
Matter (Motor)
More (Motor)