Cranial Nerves

Question 1

What is the 7th (VII) cranial nerve and does it have sensory, motor or both functions?

Answer 1

Facial, both

Question 2

What is the route of CN VII?

Answer 2

It travels through the internal acoustic meatus exiting the skull through the stylomastoid foramen

Question 3

How many branches of CN VII are there?

Answer 3

3 in the ear

and 5 in the face after passing through the parotid gland

Question 4

What are the branches of CN VII in the face?

Answer 4

Temporal
Zygomatic
Buccal
Mandibular
Cervical

Question 5

What is the 10th (X) cranial nerve and does it have sensory, motor or both functions?

Answer 5

Vagus, both

Question 6

What is the motor function of CN VII?

Answer 6

Supply the muscles of facial expression and the stapedius muscles of the middle ear

Question 7

What is the sensory function of CN VII?

Answer 7

Sensory to the anterior 2/3 of the tongue providing taste sensation

Question 8

What other function does CN VII have excluding motor and sensory?

Answer 8

Provides parasympathetic fibres to salivary glands

Question 9

What is the 9th (IX) cranial nerve and does it have sensory, motor or both functions?

Answer 9

Glossopharyngeal, both

Question 10

What is the motor function of CN IX?

Answer 10

Motor to stylopharyngeus to shorten and widen pharynx and elevate larynx

Question 11

What are the 2 main sensory functions of CN IX?

Answer 11

1. Provides taste and general sensation to the posterior 1/3rd of the tongue
2. Supplies the carotid sinus and carotid body which helps to control blood pressure, pulse and respiration

Question 12

What parasympathetic function does CN IX have?

Answer 12

Provides parasympathetic innervation to the parotid gland

Question 13

What is the motor supply of CN X?

Answer 13

Motor to majority of muscles of pharynx and larynx by recurrent laryngeal or external branch of superior laryngeal nerve

Question 14

What is the sensory function of CN X?

Answer 14

Sensory to larynx

Question 15

What is the parasympathetic function of CN X?

Answer 15

Parasympathetic to internal viscera up to 2/3rds of the transverse colon

Question 16

What is the acoustic reflex?

Answer 16

Loud noise is heard in outer ear, vibrations travel and hit tympanic membrane, vibrations hit ossicles of the ear (malleus, incus and stapes), stapedius muscle contracts to prevent inner ear damage

Question 17

What is the 5th (V) cranial nerve and does it have sensory, motor or both functions?

Answer 17

Trigeminal, both

Question 18

What are the branches of CN V?

Answer 18

V1 - Ophthalmic
V2 - Maxillary
V3- Mandibular

Question 19

What is the sensory function of CN V?

Answer 19

Innervates the skin, mucous membranes and sinuses of the face

Question 20

How do you test cranial nerve IX and X?

Answer 20

By assessing the soft palate and testing the gag reflex

Question 21

How do you test cranial nerve V and its branches?

Answer 21

Light touch on the forehead, cheek and jaw

Question 22

How do you test cranial nerve VII?

Answer 22

Test muscles of facial expression. Ask them if they have noticed any hearing changes

Question 23

How do you test cranial nerves III, IV and VI?

Answer 23

Look to see if there is any eyelid drooping and ask the patient to follow a H shape with their eyes only