Cranial Nerves Chart & Assessment Cheat Sheet (2026)

The cranial nerves run sensory and motor functions across the head and neck, and assessing them is how you catch neurological deficits early. This is the reference chart: each nerve, what it does, and how you test it.

What Are Cranial Nerves?

There are 12 pairs of cranial nerves, named or numbered CN I through XII. Each is sensory, motor, or both. They carry vision, hearing, taste, and smell to the brain, and they drive facial expression, eye movements, chewing, swallowing, and speech.

Equipment

• Snellen or visual acuity chart
• Penlight
• Ophthalmoscope
• Cotton swab or cotton ball
• Tuning fork (Weber and Rinne tests)
• Tongue depressor
• Odorants (olfactory testing)
• Taste strips or solutions (gustatory testing)
• Reflex hammer
• Ophthalmic ruler (pupil size)
• Gauze or tissue
• Gloves

The 12 Cranial Nerves

Numbered I through XII, front to back. Each entry covers origin, function, and what to assess.

I: Olfactory Nerve

Originates from the olfactory epithelium in the nasal cavity and passes through the cribriform plate of the ethmoid bone. Carries smell from the nasal mucosa to the olfactory bulbs in the brain.

II: Optic Nerve

Arises from the retina and runs through the optic canal to the optic chiasm. Carries visual information from the retina to the brain: light, color, and form.

III: Oculomotor Nerve

Emerges from the midbrain and passes through the superior orbital fissure. Controls most eye movements, including raising the eyelid, constricting the pupil, and shaping the lens for near vision.

IV: Trochlear Nerve

Arises from the posterior midbrain and passes through the superior orbital fissure. Innervates the superior oblique muscle, mainly responsible for downward and inward eye movement (depression and intorsion). Evaluate extraocular movements and assess for diplopia (double vision).

V: Trigeminal Nerve

Emerges from the pons with three divisions: ophthalmic (V1), maxillary (V2), and mandibular (V3), each exiting through separate foramina. Sensory function covers facial touch, pain, and temperature for the forehead, eyes, nose, cheeks, and lower jaw. It also innervates the muscles of mastication for chewing.

VI: Abducens Nerve

Arises from the pons and passes through the superior orbital fissure. Innervates the lateral rectus muscle, responsible for abduction (outward movement) of the eye. Evaluate extraocular movements and assess for nystagmus (involuntary eye movements).

VII: Facial Nerve

Emerges from the pons and exits through the stylomastoid foramen. Controls facial expression and taste. Assess facial symmetry, taste on the anterior two-thirds of the tongue, and the ability to close the eyes tightly.

VIII: Vestibulocochlear Nerve

Arises from the brainstem and enters the inner ear. Controls hearing and balance. Evaluate auditory acuity, the Weber and Rinne tests, and balance and coordination.

• Rinne test. Compares air conduction (tuning fork near the ear) to bone conduction (tuning fork on the mastoid bone). Normally, air conduction is heard longer. If bone conduction is heard longer, it indicates conductive hearing loss; if air conduction is heard longer but sound does not reach the inner ear properly, it indicates sensorineural hearing loss.
• Weber test. A vibrating tuning fork is placed on the forehead or midline of the skull to assess sound localization. If the sound is heard equally in both ears, hearing is normal or symmetric. If the sound lateralizes to one ear, it may indicate conductive hearing loss in that ear or sensorineural hearing loss in the opposite ear.

IX: Glossopharyngeal Nerve

Emerges from the medulla oblongata and exits through the jugular foramen. Controls taste for the posterior one-third of the tongue, assists swallowing, and innervates the carotid body and sinus for blood pressure regulation.

X: Vagus Nerve

Emerges from the medulla oblongata and exits through the jugular foramen. Drives autonomic functions like heart rate, digestion, and respiratory rate, and innervates the pharynx and larynx muscles for speech and swallowing.

XI: Accessory Nerve

Originates from the medulla oblongata and the upper spinal cord, ascends through the foramen magnum, and exits through the jugular foramen. Controls the sternocleidomastoid and trapezius muscles for head movement and shoulder shrugging.

XII: Hypoglossal Nerve

Emerges from the medulla oblongata and exits through the hypoglossal canal. Controls tongue movement for speech, swallowing, and manipulating food during chewing.

Cranial Nerve Assessment	Normal Response	Documentation
Ask client to protrude tongue at midline and then move it side to side.	The client should be able to move tongue without any difficulty.	The client was able to move tongue in different directions.