Cranial nerves

Question 1

Cranial nerve I

Answer 1

Olfactory- responsible for sensory nerve of smell

Question 2

Cranial nerve II

Answer 2

Optic- 2 optic nerves unite to form an optic chiasm, fibers cross and form an optic tract on either side

Question 3

Most optic nerve fibers terminate on the __________, and then relay fibers run to visual cortex on the ________ lobe

Answer 3

Thalamus; occipital

Question 4

Cranial Nerve III

Answer 4

Oculomotor- nucleus on ventral part of midbrain, and extends to run the external eye muscles

• also contains autonomic fibers for intrinsic eye muscles (ciliary and iris)
• innervates four of the extrinsic eye muscles

Question 5

Cranial Nerve IV

Answer 5

Trochlear- cells originate on midbrain and provide motor to superior oblique muscles of the eye

Question 6

Cranial Nerve V

Answer 6

Trigeminal- 3 sensory branches carry afferent impulses from the skin and mucosa of the head and teeth to cell bodies situated on the pons

• A small motor root of CN V functions the muscles of mastification
• provides sensory innervation to the face and motor innervation to chewing muscles

Question 7

What are the 3 sensory branches of the trigeminal nerve?

Answer 7

Opthalmic, maxillary, and mandibular

Question 8

Cranial Nerve VI

Answer 8

Abducens- motor to lateral rectus muscle

Question 9

Cranial Nerve VII

Answer 9

Facial- motor fibers originate on the lower part of the pons and they extend via several branches to muscles of facial expression

• Also submaxillary and sublingual glands sensory fibers originate on the anterior 2/3 of the tongue
• innervates muscles of facial expression

Question 10

Cranial Nerve VIII

Answer 10

Acoustic

-2 distinct divisions; vestibular and cochlear

Question 11

This nerve has fibers that extend from semicircular canals to vestibular nuclei on the pons and medulla. . .

Answer 11

Vestibular (balance) -CN VIII

Question 12

Cochlear (hearing) fibers extend from ________ of _______ and terminate on cochlear nuclei between the ______ and _________

Answer 12

organ of corti; pons; medulla

CN VIII

Question 13

Cranial nerve IX

Answer 13

Glossopharyngeal

Question 14

Cranial Nerve X

Answer 14

Vagus

• Widely distributed and contains both sensory and motor fibers
• sensory
• pharynx, larynx, trachea, heart, carotid bodies, lungs, bronchi, esophagus, stomach, small intestine and gallbladder
• taste from epiglottis
• motor
• to thoracic and abdominal viscera and to muscles of swallowing (pharynx and larynx)
• a mixed sensory and motor nerve wanders into thorax and abdomen
• PNS innervation of organs

Question 15

Cranial Nerve XI

Answer 15

Spinal Accessory-

• Part of fibers originate in the cells of the medulla and eventually join with the vagus for abdominal and thoracic viscera
• motor fibers originate on the cervical cord to the trapezius and sternocleidomastoid

Question 16

What nerve innervates the trapezius muscle?

Answer 16

Accessory Nerve

Question 17

Cranial Nerve XII

Answer 17

Hypoglossal

• cell nucleus in medulla to the muscles of the tongue
• runs inferior to the tongue- innervate the tongue muscles

Question 18

What nerve is tested by having the pt. sniff coffee grounds or vanilla?

Answer 18

Cranial Nerve I- olfactory

Question 19

What nerve is tested using fundoscopy?

Answer 19

Cranial nerve II- Optic. Along with eye charts and visual fields

Question 20

Pupillary reflexes are tested by. . .

Answer 20

testing constriction to light- CNIII

Question 21

Having a pt. follow your finger is testing. . .

Answer 21

CNIII ocularmotor- test along with nerves IV and VI for extraocular movements

Question 22

This nerve is motor to the oblique, you test it with EOMs. A problem occurs if the eye cant go down and out. . .

Answer 22

Cranial Nerve IV- Trochlear

Question 23

This is the largest Cranial nerve, sensory to the face, and has 3 divisions. . .

Answer 23

CN V- Trigeminal

Question 24

What are the 3 divisions of the “tri”geminal?

Answer 24

VI- ophthalmic
V2 maxillary
V3 mandibular

Question 25

To test V3, what should you have the patient do?

Answer 25

clench teeth, open mouth against resistance, move jaw side to side

Question 26

This nerve is responsible for motor to lateral rectus of eye, abducts eye outward. . .

Answer 26

CN VI- Abducens

Question 27

Which nerves are mixed motor and sensory?

Answer 27

VII- facial, IX- glossopharyngeal, X- vagus

Question 28

This nerve is motor for facial expression, symmetry, tearing and taste of anterior 2/3 of tongue

Answer 28

VII- facial

Question 29

You test this nerve by using a tuning fork. . .

Answer 29

VIII- Vestibulocochlear

Question 30

The other 1/3 of the tongue, along with motor for uvula, gag reflex and cough are due to this nerve

Answer 30

IX- glossopharyngeal

Question 31

If a pt. can stick their tongue out straight, this nerve is intact. . .

Answer 31

XII- hypoglossal

Question 32

"Spinal accessory," responsible for shoulder shrugging, and head rotation

Answer 32

XI- accessory

Question 33

What 2 muscles are innervated with the accessory nerve?

Answer 33

Sternocleidomastoid and trapezius

Question 34

If this nerve is stimulated, your patient may have decreased HR?

Answer 34

X- vagus

Question 35

This nerve moves the eyes, adduction of the eye (medial rectus and plays a roll in pupil size?

Answer 35

III- oculomotor

Question 36

What are the muscles paired with the oculomotor nerve?

Answer 36

``` Superior rectus Inferior oblique Inferior rectus Medial rectus Levator palpebrae superioris ```

Question 37

T/F the abducent causes abduction of the eyeball.

Answer 37

True

Question 38

What nerve causes adduction of the eyeball?

Answer 38

CN III- Oculomotor