Cranial Nerves

Question 1

What is cranial nerve I and what is its function?

Answer 1

• Olfactory

- Carries afferent impulses for sense of smell

Question 2

What is cranial nerve II and what is its function?

Answer 2

• Optic

- Carries afferent impulses for sense of vision

Question 3

What is cranial nerve III and what is its function?

Answer 3

• Occuolomotor
• Supplies 4/6 extrinsic muscles that move the eyeball in the orbit
• PS fibres for pupil constriction & lens shape

Question 4

What is cranial nerve IV and what is its function?

Answer 4

• Trochlear

- Innervates the superior oblique muscle of the eye

Question 5

What is cranial nerve V and what is its function?

Answer 5

• Trigeminal
• 3 branches (opthamalic, maxillary, mandibular)
• Supplies sensory fibres to the face & motor fibres to the chewing muscles

Question 6

What is cranial nerve VI and what is its function?

Answer 6

• Abducens

- Controls the extrinsic eye muscle that abducts the eyeball (turns it laterally)

Question 7

What is cranial nerve VII and what is its function?

Answer 7

• Facial

- Innervates the muscles of facial expression, carries sensory impulses from taste buds

Question 8

What is cranial nerve VIII and what is its function?

Answer 8

• Vestibulocochlear

- Sensory nerve for hearing & balance

Question 9

What is cranial nerve IX and what is its function?

Answer 9

• Glossopharangeal

- Innervates part of the tongue & pharynx, carries sensory impulses from taste buds

Question 10

What is cranial nerve X and what is its function?

Answer 10

• Vagus
• Only cranial nerve that extends beyond head/neck
• PS fibres to heart, lungs & abdominal viscera for breathing, heart rate & digestion
• Transmits sensory information from thoracic/abdominal viscera, aortic arch baroreceptors (BP), carotid/aortic bodies (respiration) & taste buds

Question 11

What is cranial nerve XI and what is its function?

Answer 11

• Accessory
• Accessory to the vagus nerve
• Supplies motor fibres to trapezius & SCM

Question 12

What is cranial nerve XII and what is its function?

Answer 12

• Hypoglossal
• Runs inferior to the tongue
• Innervates the tongue muscles for chewing, swallowing & speech

Question 13

Does the olfactory nerve have sensory or motor functions (or both)?

Answer 13

Sensory only (smell)

Question 14

Does the optic nerve have sensory or motor functions (or both)?

Answer 14

Sensory only (vision)

Question 15

Does the oculomotor nerve have sensory or motor functions (or both)?

Answer 15

Motor only

Question 16

Does the trochlear nerve have sensory or motor functions (or both)?

Answer 16

Motor only

Question 17

Does the trigeminal nerve have sensory or motor functions (or both)?

Answer 17

Sensory (general sensation) & motor

Question 18

Does the abducens nerve have sensory or motor functions (or both)?

Answer 18

Motor only

Question 19

Does the facial nerve have sensory or motor functions (or both)?

Answer 19

Sensory (taste) & motor

Question 20

Does the vestibulocochlear nerve have sensory or motor functions (or both)?

Answer 20

Sensory (hearing & balance) & some motor function

Question 21

Does the glossopharyngeal nerve have sensory or motor functions (or both)?

Answer 21

Sensory (taste) & motor

Question 22

Does the vagus nerve have sensory or motor functions (or both)?

Answer 22

Sensory (taste) & motor

Question 23

Does the accessory nerve have sensory or motor functions (or both)?

Answer 23

Motor only

Question 24

Does the hypoglossal nerve have sensory or motor functions (or both)?

Answer 24

Motor only