Cranial Nerves: Quick Reference Summary

Cranial Nerves $I$ to $IV$

• $I$ Olfactory (OME): Sensory ($S$). Assessment involves identifying familiar smells like coffee or vanilla.

• $II$ Optic (OPT): Sensory ($S$). Assessment includes testing visual fields and visual acuity using a Snellen chart.

• $III$ Oculomotor (OCU): Motor ($M$). Responsible for eye movement, pupil constriction, and accommodation.

• $IV$ Trochlear (TRO): Motor ($M$). Responsible for downward and inward eye movement.

Cranial Nerves $V$ to $VIII$

• $V$ Trigeminal (TRI): Both ($B$). Responsible for face sensation (tested via light touch) and chewing strength (jaw clenching).

• $VI$ Abducens (ABD): Motor ($M$). Responsible for lateral (side to side) eye movement.

• $VII$ Facial (FAC): Both ($B$). Responsible for facial expressions (smile, frown, puff cheeks) and taste on the front $\frac{2}{3}$ of the tongue.

• $VIII$ Vestibulocochlear (VES): Also known as Acoustic. Sensory ($S$). Assessment includes checking hearing via the whisper test and balance via the Romberg test.

Cranial Nerves $IX$ to $XII$

• $IX$ Glossopharyngeal (GLO): Both ($B$). Responsible for the gag reflex, swallowing, and taste on the back $\frac{1}{3}$ of the tongue.

• $X$ Vagus (VAG): Both ($B$). Responsible for voice quality, heart rate, digestion, and palate elevation (tested via the "Ahh" test).

• $XI$ Accessory (ACC): Also known as Spinal Accessory. Motor ($M$). Responsible for shrugging shoulders and turning the head against resistance.

• $XII$ Hypoglossal (HYP): Motor ($M$). Responsible for tongue movement and protrusion (sticking out the tongue and moving it side to side).