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


  • I: Olfactory
  • II: Optic
  • III: Oculomotor
  • IV: Trochlear
  • V: Trigeminal
  • VI: Abducens
  • VII: Facial
  • VIII: Oculomotor
  • IX: Glossopharyngeal
  • X: Vagus
  • XI: Accessory
  • XII: Hypoglossal


Cribriform foraminaCN I
Optic CanalCN II
Superior Orbital FissureCN III




Foramen rotundumCN V2
Foramen ovaleCNV3
Internal acoustic meatusCN VII CN VIII
Jugular foramenCN IX CN X CN XI
Foramen magnumCN XI
Hypoglossal canalCN 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 NerveFunctional FibersExit from SkullFunctions
Olfactory (I)Cribriform place of ethmoidSmell
Optic (II)Optic canalVision
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)SOFSuperior oblique
Trigeminal (V)

– Ophthalmic (V1)

– Maxillary (V2)

– Mandibular (V3)





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 NerveFunctional FibersExit from SkullFunctions
Abducens (VI)SOFLateral rectus
Facial (VII)GSA, SVE, SVA, GVEInternal acoustic meatus à Stylomastoid foramenGSA: external ear

SVE: muscles of facial expression, posterior digastric, stylohoid


SVA: taste anterior 2/3 of tongue

GVE: submandibular, sublingual, and lacrimal glands

Vestibulocochlear (VIII)SSAInternal acoustic meatusVestibular branch: balance

Cochlear branch: hearing

Glossopharyngeal (IX)GSA, GVE, SVA,Jugular foramenGSA: 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 NerveFunctional FibersExit from SkullFunctions
Vagus (X)GSA, GVA, GVE, SVA, SVEJugular foramenGSA: 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)GSEForamen magnum à Jugular foramenSternocleidomastoid and trapezius
Hypoglossal (XII)GSEHypoglossal canalHyoglossus, genioglossus, styloglossus, and intrinsic muscles of tongue

Cranial Nerves

Cranial NerveMajor FunctionExit
CN I – OlfactorySmellCribriform plate of the ethmoid
CN II – OpticVisionOptic canal
CN III – OculomotorEye movement
Superior orbital fissure
CN IVEye movement (superior oblique)Superior orbital fissure
CN V – Trigeminal, three divisions
CN V1 – OphthalmicSensorySuperior orbital fissure

Then exits supraorbital foramen as the supraorbital n.

CN V2 – MaxillarySensoryForamen rotundum

Then exits infraorbital fissure as the infraorbital n.

CN V3 – MandibularSensory & motor (mastication)Foramen ovale

Then exits mental foramen as mental n.

CN VI – AbducensEye movement (lateral rectus)Superior orbital fissure
CN VII – FacialMotor/taste
Internal auditory meatus

Then exits through stylomastoid foramen

CN VIII – VestibulocochlearHearing & balanceInternal auditory meatus
CN IX – GlossopharyngealMotor/taste
Jugular foramen
CN X – VagusMotor/taste
Jugular foramen
CN XI – Spinal accessoryMotor (sternocleidomastoid, trapezius)Jugular foramen
CN XII – HypoglossalMotor 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 NerveBrainstemNerveGanglionTarget
CN III – OculomotorBrainstemCiliary ganglionConstrict pupil
CN VII – FacialBrainstemGreater petrosal n.PterygopalatineLacrimal gland
BrainstemChorda tympani (taste)SubmandibularLingual n.
CN IX – GlossopharyngealBrainstemLesser petrosal n.Oticw/auriculotemporal branch of V3 to Parotid
CN X – VagusBrainstemNerveEntericGut stuff