12 CRANIAL NERVES

Olfactory (CN I)

• Function: Smell (sensory)

• Example: Smelling perfume or food.

Optic (CN II)

• Function: Vision (sensory)

• Example: Reading a book or seeing a stop sign.

Oculomotor (CN III)

• Function: Eye movement, pupil constriction (motor)

• Example: Looking up or down, pupils shrinking in bright light.

Trochlear (CN IV)

• Function: Eye movement (motor), controls superior oblique muscle

• Example: Looking down at your phone while keeping your head still.

Trigeminal (CN V)

• Function: Facial sensation & chewing (both sensory and motor)

• Example: Feeling your cheek when you touch it, chewing gum.

Abducens (CN VI)

• Function: Eye movement (motor), controls lateral rectus muscle

• Example: Looking sideways/outward (e.g., watching someone walk past you).

Facial (CN VII)

• Function: Facial expression, taste (front 2/3 of tongue), saliva & tears (both)

• Example: Smiling, tasting a lollipop, tearing up while laughing.

Vestibulocochlear (CN VIII)

• Function: Hearing and balance (sensory)

• Example: Listening to music or balancing while walking on a line.

Glossopharyngeal (CN IX)

• Function: Taste (back 1/3 of tongue), swallowing, salivation (both)

• Example: Swallowing food or tasting something bitter at the back of your tongue.

Vagus (CN X)

• Function: Parasympathetic control of heart, lungs, digestive tract; swallowing, speech (both)

• Example: Slowing heart rate during deep breathing or speaking clearly.

Accessory (CN XI)

• Function: Controls neck and shoulder muscles (motor)

• Example: Turning your head or shrugging your shoulders.

Hypoglossal (CN XII)

• Function: Tongue movement (motor)

• Example: Sticking out your tongue or moving it to speak or chew.