Cranial Nerves Flashcards
What is cranial nerve I?
Olfactory nerve
How do you test cranial nerve I?
Test sense of smell using familiar scents (e.g., coffee, vanilla).
Where is cranial nerve I located?
Located in the forebrain (cerebrum, anterior to midbrain).
What is cranial nerve II?
Optic nerve
How do you test cranial nerve II?
Test visual acuity (Snellen chart), visual fields, and pupillary light reflex.
Where is cranial nerve II located?
Located at the diencephalon, just anterior to the midbrain.
What is cranial nerve III?
Oculomotor nerve
How do you test cranial nerve III?
Test eye movements (up, down, medial), pupil constriction, and eyelid elevation.
Where is cranial nerve III located?
Located at the midbrain.
What is cranial nerve IV?
Trochlear nerve
How do you test cranial nerve IV?
Test downward and inward eye movement by asking the patient to look at their nose.
Where is cranial nerve IV located?
Located at the midbrain.
What is cranial nerve V?
Trigeminal nerve
How do you test cranial nerve V?
Test facial sensation (light touch, pinprick), and jaw strength (clench teeth).
Where is cranial nerve V located?
Located at the pons.
What is cranial nerve VI?
Abducens nerve
How do you test cranial nerve VI?
Test lateral eye movement by asking the patient to look sideways.
Where is cranial nerve VI located?
Located at the pons.
What is cranial nerve VII?
Facial nerve
How do you test cranial nerve VII?
Test facial expressions (smile, frown, puff cheeks) and taste on anterior 2/3 of tongue.
Where is cranial nerve VII located?
Located at the pons.
What is cranial nerve VIII?
Vestibulocochlear nerve
How do you test cranial nerve VIII?
Test hearing with tuning fork (Rinne/Weber tests) and balance (Romberg test).
Where is cranial nerve VIII located?
Located at the pons-medulla junction.
What is cranial nerve IX?
Glossopharyngeal nerve
How do you test cranial nerve IX?
Test gag reflex, swallowing, and taste on posterior 1/3 of tongue.
Where is cranial nerve IX located?
Located at the medulla.
What is cranial nerve X?
Vagus nerve
How do you test cranial nerve X?
Test swallowing, phonation (say ‘ahh’), and uvula elevation.
Where is cranial nerve X located?
Located at the medulla.
What is cranial nerve XI?
Accessory nerve
How do you test cranial nerve XI?
Test shoulder shrug (trapezius) and head-turning strength (sternocleidomastoid).
Where is cranial nerve XI located?
Located at the medulla.
What is cranial nerve XII?
Hypoglossal nerve
How do you test cranial nerve XII?
Test tongue movements by asking the patient to stick out their tongue.
Where is cranial nerve XII located?
Located at the medulla.
What cranial nerves are involved in the pupillary light reflex?
Cranial nerves II (optic) and III (oculomotor).
How do you test the pupillary light reflex?
Shine a light into one eye and observe for pupillary constriction in both eyes.
What cranial nerves are involved in the corneal reflex?
Cranial nerves V (trigeminal) and VII (facial).
How do you test the corneal reflex?
Lightly touch the cornea with a cotton wisp and observe for blinking.
What cranial nerves are involved in the oculocephalic reflex (doll’s eyes)?
Cranial nerves III (oculomotor), IV (trochlear), and VI (abducens).
How do you test the oculocephalic reflex?
Turn the patient’s head side-to-side; eyes should move opposite to the head direction.
What cranial nerves are involved in the cold caloric reflex?
Cranial nerves III (oculomotor), IV (trochlear), VI (abducens), and VIII (vestibulocochlear).
How do you test the cold caloric reflex?
Instill cold water into the ear canal and observe for eye deviation toward the stimulated ear.
What cranial nerves are involved in the gag reflex?
Cranial nerves IX (glossopharyngeal) and X (vagus).
How do you test the gag reflex?
Stimulate the back of the throat and observe for gagging or uvula elevation.
