The 12 Cranial Nerves

Cranial Nerves- Summary Notes

I. Olfactory (Sensory/Afferent)

• Function: Sense of smell

II. Optic (Sensory/Afferent)

• Function: Sense of sight

III. Oculomotor (Motor/Efferent)

• Functions:

  • Raises eyelids/eyebrows

  • Focuses lens

  • Pupil constriction

IV. Trochlear (Motor/Efferent)

• Function: Moves eyes up and down

V. Trigeminal (Sensory & Motor – Mixed)

• Sensory: Transmits impulses from scalp, forehead, upper lip

• Motor: Muscles of mastication & tongue sensation

VI. Abducens (Motor/Efferent)

• Function: Moves eyes side to side (abduction)

VII. Facial (Sensory & Motor – Mixed)

• Sensory: Taste (anterior 2/3 of tongue)

• Motor: Muscles of facial expression, tear glands, salivary glands

VIII. Vestibulocochlear (Sensory/Afferent – Auditory Nerve)

• Functions: Balance & hearing

IX. Glossopharyngeal (Sensory & Motor – Mixed)

• Sensory: Back of throat, tonsils, tongue, carotid artery

• Motor: Assists swallowing

X. Vagus (Sensory & Motor – Mixed, largest nerve)

• Functions:

  • Swallowing, coughing, speech

  • Autonomic control: Heart, smooth muscles, glands

XI. Accessory (Motor/Efferent – Spinal Accessory)

• Function: Controls muscles of the shoulder and back

XII. Hypoglossal (Motor/Efferent)

• Function: Controls muscles that move the tongue.