Cranial nerves

Question 1

Name the 12 cranial nerves?

Answer 1

1. Olfactory
2. Optic
3. Occulomotor
4. Trochlear
5. Trigeminal
6. Abducens
7. Facial
8. Vestibiculococchlear
9. Glossopharyngeal
10. Vagus
11. Accessory
12. Hypoglossal

Question 2

What is Cranial nerve I?

Answer 2

Name: Olfactory
Location: cribriform plate (originates from cerebrum)
Sensory or motor ./ function : Sensory and smell
Test : Smelling distinctive food items

Question 3

What is Cranial nerve II?

Answer 3

Name: Optic
Location: Optic canal
Sensory or motor ./ function : Sensory / vision
Test : Snellen Chart - test at various distances

Question 4

What is cranial nerve III?

Answer 4

Name : Occulomotor
Location: Superior orbital fissure
Sensory or motor/ function: Motor , extrinsic eye muscles and levator palperbrae superioris, pupillary sphincter
Test: use light to see if pupils dilate. Ask patient to follow fingers without moving their head.

Question 5

What is cranial nerve IV?

Answer 5

Name : Trochlear
Location: Syperior orbital fissure
Sensory or motor/ function: Motor / superior oblique
Test: hearing different frequency using tuning fork

Question 6

What is cranial nerve V?

Answer 6

Name : Trigmenial ‘
Maxillary : cheeks, lower eye lid, nasal mucosa, upper lip, upper teeth and palate
Location : forem rotundum
Mandibular : Anterior 2/3 of tongue, skin over mandible and lower teeth . Muscles of mastication,
Location: Forem ovale
Location: Superior orbital fissure
Sensory or motor/ function: Sensory and motor
Test: Cotton pad / light and hard object on face of patient. Ask them to close their eyes and see if they feel anything / any pressure

mandibular : ask patient to clench jaw as much as possible. Ask patient to puff up cheeks as much as possible and squeeze

Question 7

What is cranial nerve VI?

Answer 7

Name : Abducens
Location: Superior orbital fissure
Sensory/ motor. Function : Motor. Lateral rectus
Test : Hold finger 30 to cm in front of patient and move it . Tell patient to follow finger with their eyes without moving their heads.

Question 8

What is cranial nerve VII?

Answer 8

Name : Facial
Location: internal acoustic meatus > stylomastoid
Sensory or motor/ function: both . Sesation to part of ext.ear . Taste from anterior 2/3 tongue , hard and soft palate . Muscles of facial expression. Lacrimal, submandibular, sublingual glands and mucous glands of mouth and nose.
Test: Ask patient to frown and make funny faces

Question 9

What is cranial nerve VIII?

Answer 9

Name : Vestibulocochlear
Location: Internal acoustic meatus
Sensory or motor/ function: Sensory. Hearing and balance
Test: Test the distance the patient can stop hearing the ticking of a clock or stopwatch

Question 10

What is cranial nerve IX?

Answer 10

Name : Glossopharyngeal
Location: Jugular
Sensory or motor/ function: Both. post 1/3 tongue, exterior ear and middle ear cavity. Carotid body and sinus . Taste from 1/3 tongue . Parotid gland . Stylopharyngeus.
Test: Have patient drink water and observe swallowing reflex

Question 11

What is cranial nerve X?

Answer 11

Name : Vagus
Location: Jugular
Sensory or motor/ function: Both . Exterior ear, larynx and pharynx. Thoracic and abdominal viscera. Taste from epiglottis region of tongue. Smooth muscles of pharynx, larynx and most of the GIT. Most muscles of pharynx and larynx
Test : Test for swallowing reflex. Try a few drops of salty/ sugary water on the tongue and see if the patient can taste it

Question 12

What is cranial nerve XI?

Answer 12

Name : Accessory
Location: Jugular
Sensory or motor/ function: Motor. Trapezius and sternocleidomastoid. A few fibres run with CNX to viscera.
Test: Have patient move head side to side . Apply a light pressure to the side of the patients head when the head is moved.

Question 13

What is cranial nerve XII?

Answer 13

Name : Hypoglossal
Location: hypoglossal canal
Sensory or motor/ function: motor, intrinsic and extrinsic tongue muscles ( exceot the palatoglossus)
Test: Ask patient to move tongue side to side.