CN I (1): Olfactory

• type: sensory
• function: smell
• connection to brain: inferior

CN II (2): Optic

• type: sensory
• function: functional vision
• connection to brain: diencephalon

CN III (3): Oculomotor

• type: sensory
• function: innervation of the muscles of the eye (extraocular mvt)+ pupillary reflexes (constrict/accommodate) (OPEN/CLOSE EYES)
• connection to brain: anterior midbrain
• pathway: medial longtidual fasciculus

CN IV (4): Trochlear

• type: motor (superior oblique)
• function: downward + lateral eye movements (down + towards nose)
• connection to brain: midbrain @inferiro colliculi
• pathway: medial longitudinal fasciculus

CN VI (6): Abducens

• type: motor (lateral rectus)
• function: outward lateral eye mvt (left2right)
• connection to brain: lower pons
• pathway: medial longitudinal fasciculus

Eye Movement Dysfunction: CN III (3)

• Ptosis
• Lateral deviation
• Impaired pupillary response

Eye Movement Dysfunction: CN IV (4)

• Difficulty with lateral movement
• Medial and vertical deviation
• can't look towards nose

Eye Movement Dysfunction: CN VI (6)

• Difficulty with lateral movement
• Medial deviation

CN V: Trigeminal (5)

• Type: mixed (sensory and motor)

• Function (sensory): sensation to face, head, inner oral cavity, and cornea
• function (motor): innervates masseter and temporalis muscle (CHEW FOOD)
• function (reflex): afferent limb of corneal blink reflex

• connection to brain: posterior to the midbrain
• pathway: depends on the branch (light touch, slow nociceptive, proprioceptive reflex)

CN VII: Facial (7)

• Type: mixed (sensory and motor)

• Function (sensory): taste receptons (2/3 tongue)
• function (motor): facial expressions, eyelid closing, stapedius muscle
• function (reflex): efferent limb of corneal blink reflex

• connection to brain: between pons and medulla
• pathway: depends on the branch

CN VIII: Vestibulochochlear (8)

• Type: sensory (2 branches)

• Function (auditory): information form cochlea for hearing
• function (motor): sensory info from semicircular canals
• function (reflex): afferents for vestibulo-ocular reflex (VOR)

• connection to brain: between pons and medulla
• pathway: depends on the branch

CN IX: Glossopharyngeal (9)

• Type: mixed (sensory and motor)

• Function (sensory): taste receptors (1/3 tongue)
• function (motor): swallow (1 muscle in pharynx)
• function (reflex): afferents for gag+swallow reflex

• connection to brain: nucleus ambiguous (medulla)
• pathway: depends on the branch

CN X: Vagus (10)

• Type: 2 branches mixed (sensory and motor)

• Function (visceral: sensory): taste from palate and epiglottis
• function (visceral: motor): parasympathetic to heart, GI, and pulmonary systems
• function (reflex): efferent to pharynx. larynx, and esophagus

• connection to brain: nucleus ambiguous and dorsal nuclei (medulla)
• pathway: depends on the branch

CN XI: Accessory (11)

• Type: motor
• Function: efferents to sternocleidomastoid (shoulder+neck mvt)
• connection to brain: spinal cord (C1-5)

• pathway: medial longitudinal fasciculus

CN XII: Hypoglossal (12)

• Type: motor
• Function: muscles of larynx (elevation at swallowing), tongue mvt (eat, speak, swallow)
• connection to brain: nucleus ambiguous (joins CN X)

• pathway: medial longitudinal fasciculus