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The Cranial Nerves
山东大学医学院 解剖教研室李振华
Names of cranial nerves Ⅰ Olfactory nerve Ⅱ Optic nerve Ⅲ Oculomotor nerve Ⅳ Trochlear nerve Ⅴ Trigeminal nerve Ⅵ Abducent nerve Ⅶ Facial nerve Ⅷ Vestibulocochlear nerve Ⅸ Glossopharyngeal nerve Ⅹ Vagus nerve Ⅺ Accessory nerve Ⅻ Hypoglossal nerve
Functional components General somatic afferent fibers (GSA): transmit exteroceptive an
d proprioceptive impulses from head and face to somatic sensory nuclei
Special somatic afferent fibers (SSA): transmit sensory impulses from special sense organs of vision, equilibrium and hearing to the brain
General visceral afferent fibers (GVA): transmit interoceptive impulses from the viscera to the visceral sensory nuclei
Special visceral afferent fibers (SVA): transmit sensory impulses from special sense organs of smell and taste to the brain
General somatic efferent fibers (GSE): innervate skeletal muscles of eye and tongue
Special visceral efferent fibers (SVE): transmit motor impulses from the brain to skeletal muscles derived from brachial (gill) arches of embryo. These include the muscles of mastication, facial expression and swallowing
General visceral efferent fibers (GVE): transmit motor impulses from the general visceral motor nuclei and relayed in parasympathetic ganglions. The postganglionic fibers supply cardiac muscles , smooth muscles and glands
Classification of cranial nerves Sensory cranial nerves: contain only afferent (sensory) fibers
ⅠOlfactory nerve ⅡOptic nerve Ⅷ Vestibulocochlear nerve
Motor cranial nerves: contain only efferent (motor) fibers Ⅲ Oculomotor nerve Ⅳ Trochlear nerve ⅥAbducent nerve Ⅺ Accessory nerv Ⅻ Hypoglossal nerve
Mixed nerves: contain both sensory and motor fibers--- ⅤTrigeminal nerve, Ⅶ Facial nerve, ⅨGlossopharyngeal nerve ⅩVagus nerve
Sensory cranial nervesN. Location of cell
body and axon categories
Cranial exit
Terminal nuclei
Main action
Ⅰ Olfactory cells (SVA)
Cribrifomforamina
Olfactory bulb
Smell
Ⅱ Ganglion cells (SSA)
Optic canal
Lateral geniculate body
Vision
Ⅷ Vestibular ganglion(SSA)
Internal acoustic meatus
Vestibular nuclei
Equilibrium
Cochlear ganglion (SSA)
Cochlear nuclei
Hearing
Olfactory nerve
Olfactory mucosa (SVA)→ Cribriform foramina → Olfactory bulb
Optic nerveGanglion cell (SSA) → Optic canal → Lateral geniculate body
Vestibulocochlear nerveVestibular ganglion(SSA) ↘ ↗ Vestibular nuclei Internal acoustic meatus Cochlear ganglion (SSA) ↗ ↘ Cochlear nuclei
Motor cranial nervesN. Nucleus of origin and
axon categoriesCranial exit Main action
Ⅲ Nucleus of oculomotor (GSE)
Superior orbital fissure
Motot to superior, inferior and medial recti; inferior obliquus; levator palpebrae superioris
Accessory nucleus of oculomotor (GVE)
Parasympathetic to sphincter pupillea and ciliary muscl
Ⅳ Nucleus of trochlear nerve (GSE)
Superior orbital fissure
Motor to superior obliquus
Ⅵ Nucleus of abducent nerve (GSE)
Superior orbital fissure
Motor to lateral rectus
Ⅺ Nucleus of accessory nerve (SVE)
Jugular foramen Motor to sternocleidomastoid and trapezius
Ⅻ Nucleus of hypoglossal nerve( GSE)
Hypoglossal canal Motot to muscles of tongue
Oculomotor nerve Components
General somatic efferent fibers (GSE) General visceral efferent fibers (GVE)
Main action - supplies Superior, inferior and medial recti; inferior obliquus; levator palpebrae superi
oris Sphincter pupillea and ciliary muscle
Ciliary ganglion: lies between optic nerve and lateral rectus
Oculomotor nerve
Abducent nerve
Accessory nerve
Hypoglossal nerve
Hypoglossal nerve
Oculamotor paralysis
Abducent nerve injury
Mixed cranial nerves
Trigeminal nerve
Components of fibers SVE fibers: originate from motor nucleus of trige
minal nerve, and supply masticatory muscles GSA fibers: transmit facial sensation to sensory
nuclei of trigeminal nerve, the GSA fibers have their cell bodies in trigeminal ganglion, which lies on the apex of petrous part of temporal bone
Branches Ophthalmic nerve
眼神经 ( 1, sensory) Ⅴleave the skull through the superior orbital fissure, to enter orbital cavity
Branches Frontal nerve 额神经 :
Supratrochlear nerve 滑车上神经
Supraorbital nerve 眶上神经
Lacrimal nerve 泪腺神经
Nasociliary nerve 鼻睫神经
Distribution: Sensation from cerebra
l dura mater Visual organ Mucosa of nose Skin above the eye and
back of nose
Maxillary nerve 上颌神经 ( 2, sensory)Ⅴ
Leave skull through foramen rotundum
Branches Infraorbital nerve 眶
下神经 Zygomatic nerve
颧神经 Superior alveolar nerv
e 上牙槽神经 Pterygopalatine nerve
翼腭神经
Distribution: Sensation from cerebral
dura mater Maxillary teeth Mucosa of nose and mo
uth Skin between eye and m
outh
Mandibular nerve ( 3, mixeⅤd) 下颌神经
Leave the skull through the foramen ovale to enter the infratemporal fossa
Branches Auriculotemporal nerve
耳颞神经 Buccal nerve 颊神经 Lingual nerve 舌神经 Inferior alveolar nerve 下牙槽神
经 Nerve of masticatory muscles
咀嚼肌神经
Distribution: Sensation from cerebral du
ra mater Teeth and gum of lower jaw Mucosa of floor of mouth Anterior 2/3 of tongue Skin of auricular and tempor
al regions and below the mouth
Motor to masticatory muscles, mylohyoid, and anterior belly of digastric
Facial nerve (Ⅶ)Components of fibers SVE fibers originate from nucleus of facial nerve, and supply faci
al muscles
GVE fibers derived from superior salivatory nucleus and relayed i
n pterygopalatine ganglion and submandibular ganglion. The pos
tganglionic fibers supply lacrimal, submandibular and sublingual
glands
SVA fiber from taste buds of anterior two-thirds of tongue which
cell bodies are in the geniculate ganglion of the facial nerve and
end by synapsing with cells of nucleus of solitary tract
GSA fibers from skin of external ear
Course: leaves skull throu
gh internal acoustic mea
tus, facial canal and styl
omastoid foramen, it the
n enters parotid gland w
here it divides into five br
anches which supply faci
al muscles
Branches within the facial canal Chorda tympani 鼓索 : joins lingual branch of mandibular nerve
To taste buds on anterior two-thirds of tongue
Relayed in submandibular ganglion, the postganglionic fibers supply subman
dibular and sublingual glands
Greater petrosal nerve 岩大神经 : GVE fibers pass to pterygopalatine g
anglion 翼腭神经节 and there relayed through the zygomatic and lacrimal
nerves to lacrimal gland
Stapedial nerve 镫骨肌神经 : to stapedius
Branches outside of facial canal Temporal Zygomatic Buccal Marginal mandibular Cervical
Pterygopalatine ganglion 翼腭神经节 : lies in pterygopalatine fossa under maxillary nerve
Submandibular ganglion 下颌下神经节 : lies between lingual nerve and submandibular gland
Injury to the facial nerve
Glossopharyngeal nerve (Ⅸ)Components of fibers SVE fibers: originate from nucleus ambiguus, and supply styl
opharygeus GVE fibers: arise from inferior salivatory nucleus and ralyed i
n otic ganglion, the postganglionic fibers supply parotid gland SVA fibers: arise from the cells of inferior ganglion, the centr
al processes of these cells terminate in nucleus of solitary tract, the peripheral processes supply the taste buds on posterior third of tongue
GVA fibers: visceral sensation from mucosa of posterior third of tongue, pharynx, auditory tube and tympanic cavity, carotid sinus and glomus, and end by synapsing with cells of nucleus of solitary tract
GSA fibers: sensation from skin of posterior surface of auricle and
Course: leaves the skull via jugular foramen
Branches Lingual branches 舌支 : to taste buds and mucosa of posterior thir
d of tongue Pharyngeal branches 咽支 : take part in forming the pharyngeal plex
us Tympanic nerve 鼓室神经 : GVE fibers via tympanic and lesser petro
sal nerves to otic ganglion, with postganglionic fibers via auriculotemporal ( 3) to parotid glandⅤ
Carotid sinus branch 颈动脉窦支 : innervations to both carotid sinus and glomus
Others: tonsillar and stylophayngeal branches
Otic ganglion 耳神经节 : situated just below foramen ovale
Vagus nerve (Ⅹ)components of fibers GVE fibers: originate from dorsal nucleus of vagu
s nerve, synapse in parasympathetic ganglion, short postganglionic fibers innervate cardiac muscles, smooth muscles and glands of viscera
SVE fibers: originate from ambiguus, to muscles of pharynx and larynx
GVA fibers: carry impulse from viscera in neck, thoracic and abdominal cavity to nucleus of solitary tract
GSA fiber: sensation from auricle, external acoustic meatus and cerebral dura mater
Course Exits the skull from jugular foramen Descends in the neck in carotid sheath between int
ernal (or common) carotid artery and internal jugular vein
Right vagus nerve Enter thoracic inlet on right side of trachea Travels downward posterior to right brachiocephali
c vein and superior vena cava Passes posterior to right lung root Forms posterior esophageal plexus Forms posterior vagal trunk at esophageal hiatus w
here it leaves thorax and passes into abdominal cavity, then divides into posterior gastric and celiac branches
Left vagus nerve Enter thoracic inlet between left common caroti
d and left subclavian arteries, posterior to left brachiocephalic vein
Crosses aortic arch where left recurrent laryngeal nerve branches off
Passes posterior to left lung root Forms anterior esophageal plexus Forms anterior vagal trunk at esophageal hiatu
s where it leaves thorax and passes into abdominal cavity , then divides into anterior gastric and hepatic branches
Branches in neck Superior laryngeal nerve: passes down s
ide of pharynx and given rise to Internal branch, which pierces thyrohyoid mem
brane to innervates mucous membrane of larynx above fissure of glottis
External branch, which innervates cricothyroid Cervical cardiac branches : descending to
terminate in cardiac plexus Others: auricular, pharyngeal and mening
eal branches
Superior laryngeal nerve
External branch
Internal branch
Branches in thorax Recurrent laryngeal nerves
Right one hooks around right subclavian artery, left one hooks aortic arch
Both ascend in tracheo-esophageal groove
Nerves enter larynx posterior to cricothyroid joint, the nerve is now called inferior laryngeal nerve
Innervations: laryngeal mucosa below fissure of glottis , all laryngeal laryngeal muscles except cricothyroid
Bronchial and esophageal branches
Branches in abdomen Anterior and posterior gastric
branches Run close to lesser curvature an
d innervate anterior and posterior surfaces of stomach
As far as pyloric antrum to fan out into branches in a way like the digits of a crow’s foot to supply pyloric part
Hepatic branches: join hepatic plexus and then supply liver and gallbladder
Celiac branches: send branches to celiac plexus to be distributed with sympathetic fibers to liver, pancreas, spleen, kidneys, intestine as far as left colic flexure