Functional fiber types:
- General somatic efferent (GSE): skeletal muscle
- General somatic afferent (GSA): sensory from skin
- General visceral efferent (GVE): glands, smooth/cardiac muscle ANS
- General visceral afferent (GVA): sensory from viscera
- Special somatic afferent (SSA): vision, hearing, balance
- Special visceral afferent (SVA): taste, olfaction
Overview:
- I: Olfactory
- II: Optic
- III: Oculomotor
- IV: Trochlear
- V: Trigeminal
- VI: Abducens
- VII: Facial
- VIII: Oculomotor
- IX: Glossopharyngeal
- X: Vagus
- XI: Accessory
- XII: Hypoglossal
Foramina
| Foramina | CN(s) |
| Cribriform foramina | CN I |
| Optic Canal | CN II |
| Superior Orbital Fissure | CN III
CN IV CN V1 CN VI |
| Foramen rotundum | CN V2 |
| Foramen ovale | CNV3 |
| Internal acoustic meatus | CN VII CN VIII |
| Jugular foramen | CN IX CN X CN XI |
| Foramen magnum | CN XI |
| Hypoglossal canal | CN XII |
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Sensory supply to the face
- Ophthalmic N. (V1) – sensory
- Supraorbital N.
- Supratrochlear N.
- Maxillary N. (V2) – sensory
- Infraorbital N.
- Mandibular N. (V3) – mixed
- Mental N. (sensory only)
- Auriculotemporal N.
Sensory supply to the posterior scalp
- CN V1
- Greater occipital N. (DPR C2)
- Lesser occipital N. (VPR C2,[3])
- 3rd occipital N. (DPR C3)
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| Cranial Nerve | Functional Fibers | Exit from Skull | Functions |
| Olfactory (I) | Cribriform place of ethmoid | Smell | |
| Optic (II) | Optic canal | Vision | |
| Oculomotor (III) | Superior orbital fissure (SOF) | GSE: superior rectus, inferior rectus, medial rectus, inferior oblique, levator palpebrae superioris
GVE: sphincter pupillae, ciliary muscles |
|
| Trochlear (IV) | SOF | Superior oblique | |
| Trigeminal (V)
– Ophthalmic (V1) – Maxillary (V2) – Mandibular (V3) |
GSA
GSA GSA, SVE |
SOF
F. rotundum F. ovale |
Eyes, anterior scalp, upper eyelid, tip & dorsum of nose
Lower eyelid, cheek, upper lip GSA: lower face, lower lip, anterior ear, anterior 2/3 of tongue SVE: temporalis, masseter, pterygoids, anterior digastric, mylohyoid & 2 tensors |
| Cranial Nerve | Functional Fibers | Exit from Skull | Functions |
| Abducens (VI) | SOF | Lateral rectus | |
| Facial (VII) | GSA, SVE, SVA, GVE | Internal acoustic meatus à Stylomastoid foramen | GSA: external ear
SVE: muscles of facial expression, posterior digastric, stylohoid stapedius SVA: taste anterior 2/3 of tongue GVE: submandibular, sublingual, and lacrimal glands |
| Vestibulocochlear (VIII) | SSA | Internal acoustic meatus | Vestibular branch: balance
Cochlear branch: hearing |
| Glossopharyngeal (IX) | GSA, GVE, SVA, | Jugular foramen | GSA: posterior 1/3 of tongue, oropharynx, middle ear
GVA: carotid body and sinus GVE: parotid gland SVA: taste posterior 1/3 of tongue SVE: stylopharyngeus |
| Cranial Nerve | Functional Fibers | Exit from Skull | Functions |
| Vagus (X) | GSA, GVA, GVE, SVA, SVE | Jugular foramen | GSA: laryngopharynx, larynx, EAM
GVA: thoracic, foregut, and midgut viscera GVE: smooth muscle of thoracic, foregut, midgut viscera SVA: taste epiglottis and root of tongue SVE: muscles of soft palate, pharynx, and larynx |
| Accessory (XI) | GSE | Foramen magnum à Jugular foramen | Sternocleidomastoid and trapezius |
| Hypoglossal (XII) | GSE | Hypoglossal canal | Hyoglossus, genioglossus, styloglossus, and intrinsic muscles of tongue |
Cranial Nerves
| Cranial Nerve | Major Function | Exit |
| CN I – Olfactory | Smell | Cribriform plate of the ethmoid |
| CN II – Optic | Vision | Optic canal |
| CN III – Oculomotor | Eye movement Parasympathetic |
Superior orbital fissure |
| CN IV | Eye movement (superior oblique) | Superior orbital fissure |
| CN V – Trigeminal, three divisions | ||
| CN V1 – Ophthalmic | Sensory | Superior orbital fissure
Then exits supraorbital foramen as the supraorbital n. |
| CN V2 – Maxillary | Sensory | Foramen rotundum
Then exits infraorbital fissure as the infraorbital n. |
| CN V3 – Mandibular | Sensory & motor (mastication) | Foramen ovale
Then exits mental foramen as mental n. |
| CN VI – Abducens | Eye movement (lateral rectus) | Superior orbital fissure |
| CN VII – Facial | Motor/taste Parasympathetic |
Internal auditory meatus
Then exits through stylomastoid foramen |
| CN VIII – Vestibulocochlear | Hearing & balance | Internal auditory meatus |
| CN IX – Glossopharyngeal | Motor/taste Parasympathetic |
Jugular foramen |
| CN X – Vagus | Motor/taste Parasympathetic |
Jugular foramen |
| CN XI – Spinal accessory | Motor (sternocleidomastoid, trapezius) | Jugular foramen |
| CN XII – Hypoglossal | Motor of the tongue (except palatoglossus) | Hypoglossal canal |
Autonomic nerve supply:
- Parasympathetic fibers (GVE): CNIII, VII, IX, and X (fibers hitchhike on V)
- Sympathetic fibers: synapse in superior cervical ganglion
- Postganglionic fibers hitchhike on arteries
Cranial Parasympathetics
| Cranial Nerve | Brainstem | Nerve | Ganglion | Target |
| CN III – Oculomotor | Brainstem | Ciliary ganglion | Constrict pupil | |
| CN VII – Facial | Brainstem | Greater petrosal n. | Pterygopalatine | Lacrimal gland |
| Brainstem | Chorda tympani (taste) | Submandibular | Lingual n. | |
| CN IX – Glossopharyngeal | Brainstem | Lesser petrosal n. | Otic | w/auriculotemporal branch of V3 to Parotid |
| CN X – Vagus | Brainstem | Nerve | Enteric | Gut stuff |