Cranial Nerves

Question 1

I

Answer 1

Olfactory Nerve (Sensory)
Function: Responsible for sense of smell.
Test: Ask the patient to identify familiar smells (e.g., coffee, vanilla).

Question 2

II

Answer 2

Optic Nerve (Sensory)
Function: Responsible for vision
Test: Check visual acuity (Snellen chart, reading & colour).
Check visual field.
Perform ophthalmoscopy

Question 3

III

Answer 3

Oculomotor Nerve (Motor)
Function: Controls most eye movements (4/6 extraocular eye muscles), pupil constriction, and maintains an open eyelid.
Test: Check pupillary reflex (direct and indirect)
Assess for ptosis
Assess H pattern and eye convergence

Question 4

IV

Answer 4

Trochlear (Motor)
Function: Controls the superior oblique muscle, responsible for downward and inward eye movement.
Test: H pattern

Question 5

V

Answer 5

Trigeminal (Both)
Function: Sensation in the face and motor control of the muscles used for chewing.
Test: Test facial sensation in all three divisions (ophthalmic, maxillary, mandibular) and ask the patient to clench their jaw.

Question 6

VI

Answer 6

Abducens (Motor)
Function: Controls lateral eye movement (lateral rectus muscle).
Test: H pattern

Question 7

VII

Answer 7

Facial (Both)
Function: Controls facial expressions, and taste from the anterior two-thirds of the tongue.
Test: Ask pt to smile and frown

Question 8

VIII

Answer 8

Vestibulocochlear (sensory)
Function: Responsible for hearing and balance.
Test: Perform a hearing test (whisper test, tuning fork) and balance test (Romberg’s test).

Question 9

IX

Answer 9

Glossopharyngeal (Both)
Function: Sensation from the pharynx, taste from the posterior third of the tongue, and helps control swallowing. Baroreceptors in the carotid.
Test: Check gag reflex, ask the patient to swallow, and test taste on the posterior tongue.
Potentially assess BP on standing and exercise.

Question 10

X

Answer 10

Vagus (Both)
Function: Controls the muscles of the throat, heart, lungs, and digestive tract.
Test: Check the patient’s ability to speak, swallow, and say “Ah” while observing palate movement.

Question 11

XI

Answer 11

Accessory (Motor)
Function: Controls the sternocleidomastoid and trapezius muscles, facilitating shoulder shrug and head turn.
Test: Ask the patient to shrug their shoulders and turn their head against resistance.

Question 12

XII

Answer 12

Hypoglossal
Function: Controls tongue movements.
Test: Ask the patient to stick out their tongue then move it side-to-side and observe for any deviation.