CNs: III, IV, VI, XII

Function: extraocular muscles, intrinsic tongue muscles (from occipital somites)

Brainstem Nuclei: oculomotor (III), trochlear (IV), abducens (VI), hypoglossal (XII)

Nuclei are all near midline

Innervate striated muscle

Most medial motor column

AKA special visceral efferent

CNs: V, VII, IX, X, XI

Functions: muscles of mastication, facial expression, middle ear, pharynx, larynx, sternomastoid, upper portion of trapezius

Brainstem Nuclei: motor nucleus (V), Facial nucleus (VII), nucleus ambiguus (IX, X), accessory spinal nucleus (XI)

Innervate striated muscle

Most lateral motor column 

AKA general visceral efferent

CNs: III, VII, XI, X

Functions: Parasympathetic innervation of head and thoracoabdominal viscera above splenic flexure

Brainstem Nuclei: Edinger-Westphal nucleus (III), superior-salivatory nucleus (VII), Inferior salivatory nucleus (IX), Dorsal motor nucleus (X)

Do not innervate striated muscle

Second most medial motor column 

CNs: VII, IX, X

Functions: Taste

Brainstem Nuclei: nucleus solitarius (rostral portion, gustatory nucleus)

The most medial sensory column (along with general visceral afferent)

CNs: IX, X

Function: Inputs for control of cardiorespiratory and digestive functioning 

Brainstem Nuclei: Nucleus solitarius (caudal portion, cardiorespiratory nucleus)

The most medial sensory column (along with special visceral afferent)

CNs: V(primary input from here), VII, IX, X

Functions: touch, pain, temperature, position, vibration sense for face, sinuses, meninges

Brainstem Nuclei: Trigeminal nuclei 

The middle sensory column (not most lateral or most medial)

CNS: VIII

Function: olfaction, vision, hearing, vestibular sensation (olfaction and vision don't have sensory nuclei in brainstem--are in forebrain)

Brainstem Nuclei: cochlear nuclei, vestibular nuclei (olfaction and vision have no brainstem nuclei)

Most lateral sensory column 

III (oculomotor nerve)

IV (trochlear nerve)

VI (abducens nerve)

XI (spinal accessory nerve)

XII (hypoglossal nerve)

I (olfactory nerve)

II (optic nerve)

VIII (vestibulocochlear nerve)

V (trigeminal nerve)

VII (facial nerve)

IX (glossopharyngeal nerve)

X (vagus nerve)

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AKA Olfactory nerve

Functional Category: special somatic sensory

Function: olfaction

Exits from skull: cribriform plate

CNS Nucleus: olfactory bulb

Peripheral Ganglia: none

Peripheral structure innervated: olfactory receptors of olfactory epithelium

1. chemoreceptors on bipolar primary sensory neurons in olfactory neuroepithelium of upper nasal cavities
2. axons travel via olfactory nerves
3. olfactory nerves traverse the cribriform plate of the ethmoid bone
4. axons synapse in olfactory bulbs
5. info travels via olfactory tracts (between gyrus rectus and orbital frontal gyri) to the olfactory processing areas

Ansomnia = olfactory loss: if unilateral are unaware because contralateral side can compensate;

     -causes: head trauma damaging olfactory nerves as penetrate cribriform plate of the ethmoid; viral infections damage olfactory neuroepithelium, neurodegenerative conditions

     -may be a first sign of frontal lobe damage

     -ansomnia + optic atrophy in one eye = Foster Kennedy syndrome

AKA Optic nerve

Functional Category: special somatic sensory

Function: Vision

Exits from skull: optic canal (?)

CNS Nucleus: lateral geniculate nucleus

Peripheral ganglia: none

Peripheral Structure innervated: retina (ganglion cells)

Function: Carry information from retina to the lateral geniculate nucleus of the thalamus and to the extrageniculate pathways

-Portion of visual pathway in front of the optic chiasm = optic nerve

-Portion of visual pathway beyond this = optic tract

AKA Oculomotor nerve

Functional Category: Somatic motor & Parasympathetic

Somatic motor function: levator palpebrae superior and all extraocular muscles, except for superior oblique and lateral rectus 

Parasympathetic function: to pupil constrictor and ciliary muscles for near vision

Exits from skull: superior orbital fissure

Peripheral Sensory ganglia: none

CNS nucleus: oculomotor; Edinger-Westphal (in midbrain)

Peripheral autonomic ganglia: ciliary

1. Exits brainstem ventrally in the interpeduncular fossa 
2. traverse the cavernous sinus
3. exit skull via superior orbital fissure to reach muscles of orbit

-Preganglionic parasympathetic neursn in edinger-westphal nucleus of midbrain synapse in the ciliary ganglion in the orbit-->postganglionic parasympathetic fibers continue to the pupillary constrictor and ciliary muscles

AKA: Trochlear nerve

Functional Category: Somatic motor

Function: superior oblique muscle; causes depression motor and intorsion of eye; rotate top of eye medially and move it downward

Exits from skull: superior orbital fissure (like oculomotor and abducens)

CNS nucleus: trochlear

peripheral ganglia: none 

1. Exits brainstem ventrally in the interpeduncular fossa 
2. traverse the cavernous sinus
3. exit skull via superior orbital fissure to reach muscles of orbit

AKA Abducens nerve

Functional category: somatic motor

Function: lateral rectus muscle; abduction of eye

Exits from skull: superior orbital fissure (like oculomotor and trochlear)

CNS nucleus: abducens

Peripheral ganglia: none

1. Exits brainstem ventrally in the interpeduncular fossa 
2. traverse the cavernous sinus
3. exit skull via superior orbital fissure to reach muscles of orbit