The Cranial Nerves

脑 神 经

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

一嗅二视三动眼四车五叉六外展七面八听九舌咽十迷一副舌下全

Fiber components of cranial n.

General somatic afferent(sensory) fibers 一般躯体感觉纤维 Special somatic afferent (sensory) fibers 特殊躯体感觉纤维General visceral afferent (sensory) fibers 一般内脏感觉纤维Special visceral afferent (sensory) fibers 特殊内脏感觉纤维General somatic efferent (motor) fibers 一般躯体运动纤维Special visceral efferent (motor) fibers 特殊内脏运动纤维General visceral efferent (motor) fibers 一般内脏运动纤维

Classification of cranial nerves

Sensory cranial nerves 感觉性脑神经 : contain only sensory fibers

Ⅰ. Olfactory nerve

Ⅱ. Optic nerve

Ⅷ. Vestibulocochlear nerve

Classification of cranial nerves

Motor cranial nerves 运动性脑神经 : contain only motor fibers

Ⅲ. Oculomotor nerve

Ⅳ. Trochlear nerve

Ⅵ. Abducent nerve

Ⅺ. Accessory nerve

Ⅻ. Hypoglossal nerve

Classification of cranial nerves

Mixed nerves 混合性脑神经 : contain both sensory and motor fibers

Ⅴ. Trigeminal nerve

Ⅶ. Facial nerve

Ⅸ. Glossopharyngeal nerve

Ⅹ. Vagus nerve

感觉性脑神经

Sensory cranial nerves

I ． Olfactory nerve II. Optic nerveVIII.Vestibulocochlear nerve

Olfactory nerve (I)

Olfactory cell → Olfactory nerve → Cribriform foramina

筛孔 → Olfactory bulb 嗅球

Olfactory nerve

Function: conduct the smell

Optic nerve (II)Ganglion cell of retina → Optic nerve → Optic canal →视神经管optic chiasma →视交叉 optic tract → 视束 lateral geniculate body外侧膝状体 .

Vestibulocochlear nerve （ VIII ）

Cochlear ganglion

Vestibular ganglionInternal acoustic meatus

Vestibular nuclei

Cochlear nucleiVestibulocochlear nerve

Sensory cranial nerves

N. Location of cell body

Cranial exit

Terminal nuclei

Main action

Ⅰ Olfactory cellsCribrifomforamina

Olfactory bulb

Smell

Ⅱ Ganglion cells of retina

Optic canal

Lateral geniculate body

Vision

Ⅷ

Vestibular ganglion of internal ear

Internal acoustic meatus

Vestibular nuclei

Equilibrium

Cochlear ganglionof internal ear

Cochlear nuclei

Hearing

运动性脑神经 Motor cranial nerves

III.Oculomotor nerve 动眼神经IV. trochlear nerve 滑车神经 VI. Abducent nerve 展神经XI. accessory nerve 副神经XII. hypoglossal nerve 舌下神经

Oculomotor nerve （ III）

supplies : Superior, inferior and medial recti; inferior obliquus; 上直肌、下直肌、内直肌、下斜肌 levator palpebrae superioris上睑提肌 Sphincter pupillae and ciliary muscle睫状肌和瞳孔括约肌

动眼神经核

动眼神经副核

ComponentsGeneral somatic motor （ efferent ） fiber arises from oculomotor nucleus 动眼神经核General visceral motor （ efferent ） fiber arises from accessory oculomotor nucleus 动眼神经副核

Oculomotor nerve （ IV ）

Oculomotor nerve动眼神经

Course:

•Leave the brain at the interpeduncular fossa 脚间窝•Via superior orbital fissure 眶上裂 enter the orbital cavity

Ciliary ganglion睫状神经节

Oculamotor paralysis

The injury of the oculomotor n. may lead to:

Droping of the upper eyelid

上睑下垂

lateral strabismus 外斜视

Dilation of the pupil 瞳孔扩大

The pupillary reflexes disappear

瞳孔光反射消失

trochlear nerve

Trochlear nerve （ IV ）

arises from the trochlear nucleus,

and pass through the superior orbital fissure 眶上裂 to supply the superior obliquus 上斜肌

Abducent nerve

Abducent nerve （ VI ）

arises from the abducent nucleus, and pass through the superior orbital fissure to supply the lateral rectus 外直肌

Accessory nerve

Accessory nerve （ XI ）Cranial root 脑根： arises from nucleus ambiguus 疑核 ;

Spinal root 脊髓根 ： arises from the accessory nucleus 副神经核 pass through jugular foramen 颈静脉孔 ,and supplies 2 muscles

sternocleidomastoid

trapezius

Hypoglossal nerve （ XII）

Hypoglossal nerve

Hypoglossal nucleus

Hypoglossal canal

Function of Hypoglossal nerve

supplies the intrinsic and extrinsic muscles of the Tongue

extend the tongue with Contraction

So what happens if the

CN12 has been damaged ?

Motor cranial nerves

N. Nucleus of origin Cranial exit supply

Ⅲ

Oculomotor nucleus Superior orbital fissure

superior, inferior and medial recti; inferior obliquus; levator palpebrae superioris

Accessory nucleus of oculomotor (Parasympathetic )

sphincter pupillea and ciliary muscl

Ⅳ Trochlear nucleus Superior orbital fissure

superior obliquus

Ⅵ Abducent nsucleu Superior orbital fissure

lateral rectus

ⅪAccessory nucleus Jugular foramen sternocleidomastoid and tr

apezius

ⅫHypoglossal nucleus Hypoglossal canal muscles of tongue

Mixed cranial nerves

混合性脑神经

V. Trigeminal nerveVII.Facial nerveIX. Glossopharyngeal nerveX. Vagus nerve

Trigeminal nerve （ V ）

Components of fibers

General somatic afferent fibers: transmit facial sensation to sensory nuclei of trigeminal nerve, the fibers have their cell bodies in trigeminal ganglion,

Special viceral efferent fibers: originate from motor nucleus of trigeminal nerve, and supply masticatory muscles

Branches

Frontal nerve 额神经 : Supratrochlear nerve

滑车上神经Supraorbital nerve

眶上神经

Branches

Ophthalmic nerve 眼神经 (Ⅴ1, sensory)

leave the skull through the superior

orbital fissure 眶上裂 , to enter orbital cavity

Lacrimal nerve 泪腺神经 :→lacrimal gland Nasociliary nerve 鼻睫神经 ; → eyeball

Distribution:

Visual organ Part of mucosa of nose鼻粘膜 Skin above the palpebral fisure 睑裂 and back of noseCerebral dura mater 硬脑膜

Infraorbital nerve

眶下神经 Zygomatic nerve

颧神经 Superior alveolar ner

ve

上牙槽神经 Pterygopalatine nerve

翼腭神经

Maxillary nerve 上颌神经 ( 2, sensory)Ⅴ

Leave skull through foramen rotundum 圆孔

Branches

Distribution:

Maxillary teeth

Mucosa of nose and mouth

Skin between the palpebral fissure and oral fissure.

cerebral dura mater

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 mu

scles 咀嚼肌神经

Mandibular nerve 下颌神经 (Ⅴ3, mixed)

Leave the skull through the foramen ovale 卵圆孔 to enter the infratemporal fossa 颞下窝

Branches

Distribution: cerebral dura mater;

Mandibular teeth and gum 牙龈 ;

Mucosa of floor of mouth ；Anterior 2/3 of tongue;

Skin of auricular and temporal regions 耳颞区 and below the oral fissure;

masticatory muscles 咀嚼肌 , mylohyoid 下颌舌骨肌 , and anterior belly of digastric m 二腹肌前腹 .

Facial nerve (Ⅶ)

Components of fibers

Special visceral efferent fiber: fibers originate from facial nucleus 面神经核 ,

and supply facial muscles.

General visceral efferent fiber: fibers arise from superior salivatory nucleus

上泌涎核 and relayed in pterygopalatine ganglion 翼腭神经节 and submandi

bular ganglion 下颌下神经节 . The postganglionic fibers supply lacrimal 泪腺 ,

submandibular 下颌下腺 and sublingual glands 舌下腺 .

Special visceral afferent fiber: fiber from taste buds of anterior 2/3 of tongue

which cell bodies are in the geniculate ganglion 膝节 of the facial nerve and e

nd the nucleus of solitary tract 孤束核 .

General somatic afferent fiber: fibers distribute the skin of external ear.

Course: leaves skull through internal acoustic meatus 内耳门 , facial canal 面神经管 and stylomastoid foramen茎乳孔 , it then enters parotid gland 腮

腺 where it divides into five Branches which supply facial Muscles.

Chorda tympani 鼓索 : joins lingual branch of mandibular nerve

To taste buds on anterior two-thirds of tongue.

Relayed in submandibular ganglion( 下颌下神经节 ), the postgangli

onic fibers supply submandibular and sublingual glands

Branches within the facial canal

Greater petrosal nerve 岩大神经 : fibers pass to pterygopalati

ne ganglion 翼腭神经节 and the postganglionic fibers through the

zygomatic and lacrimal nerves to lacrimal gland

Stapedial nerve 镫骨肌神经 : to stapedius

Temporal branch 颞支 Zygomatic branch 颧支 Buccal branch 颊支 Marginal mandibular branch 下颌缘支 Cervical branch 颈支

Branches outside of facial canal

Pterygopalatine ganglion 翼腭神经节 : lies in pterygopalatine fossa 翼腭窝 under maxillary nerve

Submandibular ganglion 下颌下神经节 : lies between lingual nerve 舌神经 and submandibular gland 下颌下腺

Glossopharyngeal nerve ( )Ⅸ

Special visceral efferent fiber: originate from nucleus ambiguus 疑核 , and supply stylopharygeus 茎突咽肌 .

general visceral efferent fiber: arise from inferior salivatory nucleus 下泌涎核 and ralyed in otic ganglion 耳神经节 , the postganglionic fibers supply parotid gland 腮腺 .

Special visceral afferent fiber: transmit the taste of posterior third of tongue to the nucleus of solitary tract 孤束核 .

Components of fibers

Glossopharyngeal nerve ( )Ⅸ

general visceral afferent fiber: transmit the visceral sensation from mucosa of posterior third of tongue, pharynx 咽 , auditory tube 咽鼓管 and tympanic cavity 鼓室 , carotid sinus 颈动脉窦 and glomus 颈动脉小球 , to the nucleus of solitary tract.

general somatic afferent fiber: conduct the sensation from skin of posterior surface of auricle 外耳 .

Components of fibers

Branches

Lingual branches 舌支 : to taste buds and mucosa of posterior third of tongue

Pharyngeal branches 咽支 : take part in forming the pharyngeal plexus

Tympanic nerve 鼓室神经 : → tympanic cavity and auditory tube, and its general visceral motor fibers via lesser petrosal nerves to end the otic ganglion 耳神经节 , the postganglionic fibers via auriculotemporal n.( 3) Ⅴto parotid gland

Course: leaves the skull via jugular foramen

Carotid sinus branch 颈动脉窦支 : →carotid sinus and glomus

Others: tonsillar 扁桃体 and stylophayngeal branches

Otic ganglion 耳神经节 : situated just below foramen ovale

Branches

Lingual branches

Carotid sinus branch

Pharyngeal branches

Vagus nerve (Ⅹ)

general visceral efferent fiber: originate from dorsal nucleus of vagus nerve 迷走神经背核 , synapse in parasympathetic ganglion, short postganglionic fibers innervate cardiac muscles, smooth muscles and glands of visceraSpecial visceral efferent fiber: originate from the nucleus ambiguus, to muscles of pharynx and larynx

components of fibers

Vagus nerve (Ⅹ)

general visceral afferent fiber: carry impulse from viscera in neck, thoracic and abdominal cavity to nucleus of solitary tract

general somatic afferent fiber: conduct the sensation from auricle, external acoustic meatus 外耳道 and cerebral dura mater to the spinal nucleus of trigeminal n.

components of fibers

Right vagus nerve Enter thoracic cavity on right side of trachea and infront of right subclavian a. and passes posterior to right lung root

Forms posterior esophageal plexus

and posterior vagal trunk

Passes though the esophageal hiatus into abdominal cavity, then divides into posterior gastric 胃后支 and celiac branches 腹腔支

Course•Exits the skull from jugular foramen

•Descends in the neck in carotid sheath between internal (or common) carotid artery and internal jugular vein

Left vagus nerveEnter thoracic cavity between left common carotid and left subclavian arteries, Descends infront of the aortic arch

Passes posterior to the root of left lung Forms anterior esophageal plexus and anterior vagal trunk

Passes though the esophageal hiatus

into abdominal cavity, and divides into anterior gastric and hepatic branches.

External branch

Internal branch which pierces thyrohyoid

membrane to innervates mucous membrane of larynx above fissure of glottis

External branch, which innervates cricothyroid

Branches in neck

Superior laryngeal nerve 喉上神经

Internal branch

Cervical cardiac branches 颈心支 descending to terminate in cardiac plexus

Recurrent laryngeal nerves 喉返神经 Right one hooks around right subcla

vian 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 muscles except cricothyroid

Branches in thorax

Bronchial and esophageal branches

Anterior and posterior gastric branches Run close to lesser curvature and

innervate anterior and posterior surfaces of stomach

Branches in abdomen

Celiac branches:

send branches to celiac plexus whose fibers distribute with sympathetic fibers to liver, pancreas, spleen, kidneys, intestine as far as left colic flexure

Hepatic branches 肝支 : supply liver and gallbladder

Nucleus of oculomotor n.

Accessory nucleus of oculomotor n.

Inferior alveolar nerve 下牙槽神经

Auriculotemporal nerve

The nerve distribution of tongue 舌的神经分布

• Hypoglossal n. → the musels of tongue;

• Mandibular n. → anterior 2/3 mucosa of tongue;

• Facial n. → anterior 2/3 teste buds of tongue;

• Glossopharygeal n. →the mucosa and teste

buds of the root of tongue

The nerve distribution of the eyeball?III →sup. Inferior and medial rectus,inferior obliquus IV→ superior obliquus VI→lateral rectusOptic n. → visual sense;Ophthalmic n. →general sense of eyeball;sympathetic n. →dilator pupillae;parasympathetic n. →sphincter pupillae and ciliary m.