Cranial Nerves

Summary of cranial nerves

No.	Name	Components	Cells of origin	Main central connections	Exit from skull	Distribution and function
I	Olfactory	SSA	Olfactory receptor cells in nasal mucosa	To olfactory bulb, anterior perforated substance piriform cortex	Foramina of cribriform plate	Olfaction
II	Optic	SSA	Ganglion cells of retina	To lateral geniculate nucleus of Thalamus pretectal area of midbrain	Optic canal	Vision
III	Oculomotor	GSE	Oculomotor nucleus	From visual cortical areas, medial longitudinal fasciculus	Superior orbital fissure	Motor to medial rectus, inferior rectus, superior rectus, inferior oblique, levator palpebrae superioris
III	Oculomotor	GVE	Edinger–Westphal nucleus	From pretectal area of midbrain	Superior orbital fissure	Parasympathetic to sphincter pupillae and ciliary muscles, via ciliary ganglion, mediating pupillary constriction and accommodation
IV	Trochlear	GSE	Trochlear nucleus	From visual cortical areas, medial longitudinal fasciculus	Superior orbital fissure	Motor to superior oblique
Trigeminal division:
V	Ophthalmic (Vi)	GSA	Trigeminal (semilunar) ganglion	To trigeminal sensory nucleus	Superior orbital fissure	Sensation from forehead, scalp, eyelids, nose and eye, including conjunctiva
	Maxillary (Vii)	GSA	Trigeminal (semilunar) ganglion	To trigeminal sensory nucleus	Foramen rotundum	Sensation from mid-face, lower eyelid, nasal cavity and paranasal sinuses, upper lip, maxillary teeth and palate
	Mandibular (Viii)	GSA	Trigeminal (semilunar) ganglion	To trigeminal sensory nucleus	Foramen ovale	Sensation from lower face and scalp, tongue and floor of mouth, mandibular teeth and part of external ear
		GSA	Mesencephalic part of trigeminal sensory nucleus	To trigeminal sensory nucleus, cerebellum	Foramen ovale	Proprioception from muscles of mastication, temporomandibular joint
		Branchial (special visceral) efferent	Trigeminal motor nucleus	From precentral gyrus	Foramen ovale	Motor to muscles of mastication (temporalis, masseter, medial and lateral pterygoids), tensor tympani
VI	Abducens	GSE	Abducens nucleus	From visual cortical areas, medial longitudinal fasciculus	Superior orbital fissure	Motor to lateral rectus
VII	Facial	GSA	Geniculate ganglion	To trigeminal sensory nucleus, cerebellum	Internal acoustic meatus	Sensation from part of tympanic membrane, external acoustic meatus and skin behind pinna. Proprioception from facial muscles
		SVA	Geniculate ganglion	To nucleus solitarius	Internal acoustic meatus	Taste from anterior two-thirds of tongue
		GVE	Superior salivatory nucleus	From olfactory areas, nucleus solitarius	Internal acoustic meatus	Parasympathetic to lacrimal gland and mucous membrane of nasal and oral cavities (via pterygopalatine ganglion) and submandibular and sublingual salivary glands (via submandibular ganglion) causing secretion and vasodilation
		Branchial (special visceral) efferent	Facial nucleus	From precentral gyrus	Internal acoustic meatus	Motor to ‘muscles of facial expression’, stapedius, posterior belly of digastric and stylohyoid
VIII    Vestibulocochlear
	Vestibular division	SSA	Vestibular ganglion	To vestibular nuclei, cerebellum	Internal acoustic meatus	Sensations of equilibrium and motion
	Cochlear division	SSA	Spiral ganglion	To cochlear nuclei	Internal acoustic meatus	Hearing
IX	Glossopharyngeal	GSA	Glossopharyngeal ganglia	To trigeminal sensory nucleus	Jugular foramen	General sensation from posterior one-third of tongue, oropharynx and middle ear
		GVA	Glossopharyngeal ganglia	To nucleus solitarius	Jugular foramen	Sensory from carotid body (chemoreceptors) and carotid sinus (baroreceptors)
		SVA	Glossopharyngeal ganglia	To nucleus solitarius	Jugular foramen	Taste from posterior one-third of tongue
		GVE	Inferior salivatory nucleus	From olfactory areas, nucleus solitarius	Jugular foramen	Parasympathetic to parotid salivary gland (via otic ganglion), causing secretion and vasodilation
		Branchial (special visceral) efferent	Nucleus ambiguus	From precentral gyrus	Jugular foramen	Motor to stylopharyngeus
X	Vagus	GSA	Superior (jugular) ganglion	To trigeminal sensory nucleus	Jugular foramen	General sensation from pharynx, larynx, trachea, oesophagus, part of auricle and external auditory meatus
		GVA	Inferior (nodose) ganglion	To nucleus solitarius	Jugular foramen	Sensory from thoracic and abdominal viscera Sensory from aortic arch (baroreceptors) and aortic bodies (chemoreceptors)
		GVE	Dorsal motor nucleus of vagus	From hypothalamus, nucleus solitarius	Jugular foramen	Parasympathetic to glands and smooth muscle in the pharynx, larynx, thoracic and abdominal viscera
		Branchial (special visceral) efferent	Nucleus ambiguus	From precentral gyrus, sensory nuclei of brainstem	Jugular foramen	Motor to pharyngeal, external laryngeal and oesophageal striated muscles
XI       Accessory
	Cranial root	Branchial (special visceral) efferent	Nucleus ambiguus	From precentral gyrus, sensory nuclei of brainstem	Jugular foramen	Motor to muscles of soft palate and intrinsic muscles of larynx (distributed via vagus)
	Spinal root	Branchial (special visceral) efferent	Spinal cord segments C1–C5	From precentral gyrus	Jugular foramen	Motor to sternocleidomastoid and trapezius
XII	Hypoglossal	GSE	Hypoglossal nucleus	From precentral gyrus	Hypoglossal canal	Motor to all intrinsic and extrinsic muscles of the tongue, except palatoglossus

GSE : General somatic efferent

GVE : General visceral efferent

GVA : General visceral afferent

GSA : General somatic afferent

SVA : Special visceral afferent

SSA : Special somatic afferent