CRANIAL NERVES

Question 1

What are the 12 cranial nerves?

Answer 1

1) Olfactory
2) Optic
3) Oculomotor
4) Trochlear
5) Trigeminal
6) Abducense
7) Facial
8) Vestibulocochlear
9) Glossopharyngeal
10) Vagus
11) Accessory
12) Hypoglossal

Question 2

Where does the olfactory nerves exit the skull?

Answer 2

Via cribiform plate of ethmoid bone

Question 3

Where does the optic nerve leave the skull?

Answer 3

Optic canals

Question 4

Where does the oculomotor nerve exit the skull?

Answer 4

Superior Orbital fissure

Question 5

Where does the oculomotor nerve originate?

Answer 5

Originates from the medullary pontine junction and passes through the interpeduncular fossa.

Question 6

what is the function of the ocumlomotor nerve (III) ?

Answer 6

• motor controll to most of the extra-ocular muscles
• sphincter pupillae (pupil constriction)
• ciliary muscles (adjust lens)

Question 7

Where does the trochlear nerve (IV) originate from?

Answer 7

midbrain (it is the only nerve to arise from the dorsal brainstem)

Question 8

Where does the trochlear nerve exit the skull?

Answer 8

Superior Orbital fissure?

Question 9

What is the function of the trochlear nerve?

Answer 9

Innervates the superior oblique muscle

(which it depresses, abducts and medially rotates the eye)

Question 10

Describe the 3 branches of the trigeminal nerve.

Answer 10

V1 = Opthalmic (exits via superior orbital fissure)
V2 = Maxillary (exits via foramen rotundum)
V3 = Mandibular (exits via foramen Ovale)

V1, V2, V3 are all sensory branches.

V3 has motor fibres which supply the muscles of mastication including anterior belly of DIGASTRIC and MYLOHYOID

Question 11

What muscles do the motor fibres of V3 supply?

Answer 11

• anterior belly of DIGASTRIC

- MYLOhyoid

Question 12

What is the function of the ABDUCENT (VI) nerve?

Answer 12

supplies motor innervation to LATERAL RECTUS.

lateral rectus is an oculomotor muscle that causes ABDUCTION of the eyeball

Question 13

Where does the Abducent nerve exit the skull?

Answer 13

superior orbital fissure

Question 14

Where does the Abducent nerve arise from?

Answer 14

PONTO-MEDULLARY junction

Question 15

Where does the FACIAL nerve arise from?

Answer 15

Cerebellar Pontine angle

Question 16

Where does the facial nerve exit the skull?

Answer 16

First goes through the INTERNAL ACOUSTIC MEATUS and then exits skull via the STYLOMASTOID FORAMEN

Question 17

What is the funtion of the facial nerve?

Answer 17

• Taste sensation from ANTERIOR 2/3 of tongue
• innervates lacrimal, submandibular and sublingual glands
• motor to facial muscles
• motor to STYLOHYOID
• motor to posterior belly of DIGASTRIC

Question 18

Where does the Vestibulocochlear nerve (VIII) emerge from ?

Answer 18

Cerebellar pontine angle

Question 19

What is the function of the Vestibulocochlear nerve?

Answer 19

supplies the hearing and balance apparatus

Question 20

Where does the vestibulocochlear nerve leave the cranial cavity?

Answer 20

INTERNAL ACOUSTIC MEATUS

enters the petrous part of the temporal bone

Question 21

What is the function of the glossopharyngeal nerve?

Answer 21

• sensory input from POSTERIOR 1/3 of Tongue
• Sensory input from Palative Tonsils / oropharynx
• Taste from POSTERIOR 1/3 of Tongue
• Stimulate PAROTID gland

Question 22

Where does the Glossopharyngeal Nerve exit the skull?

Answer 22

Jugular Foramen

Question 23

What is the function of the Vagus nerve?

Answer 23

• sensory from larynx

- thoracic and abdo

Question 24

Where does the vagus nerve exit the skull?

Answer 24

Jugular Foramen

Question 25

What muscles does the accessory nerve innervate?

Answer 25

Trapezius

sternocleidomastoid

Question 26

Where does the accessory nerve leave the skull?

Answer 26

Jugular Foramen

Question 27

What is the function of the hypoglossal nerve?

Answer 27

-MOTOR to muscles of TONGUE

Question 28

What does the hypoglossal nerve pass through?

Answer 28

HYPOGLOSSAL CANAL