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

Sensory cranial nerves 感觉性脑神经 I．Olfactory nerve II. Optic nerve VIII.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） Vestibular nuclei Cochlear nuclei Cochlear ganglion Vestibulocochlear nerve Internal acoustic meatus Vestibular ganglion

Sensory cranial nerves Location of cell body Cranial exit Terminal nuclei Main action Ⅰ Olfactory cells Cribrifom foramina 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

Motor cranial nerves 运动性脑神经 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） Components General 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 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

Oculomotor nerve（ IV ） Course: Leave the brain at the interpeduncular fossa脚间窝 Via superior orbital fissure 眶上裂enter the orbital cavity Oculomotor nerve 动眼神经 Ciliary ganglion 睫状神经节

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 Oculamotor paralysis

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 trochlear nerve

Abducent nerve（ VI ） arises from the abducent nucleus, and pass through the superior orbital fissure to supply the lateral rectus外直肌 Abducent 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 Accessory nerve sternocleidomastoid trapezius

Hypoglossal nerve （ XII） Hypoglossal canal Hypoglossal nucleus Hypoglossal nerve

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 obliquus Ⅵ Abducent nsucleu lateral rectus Ⅺ Accessory nucleus Jugular foramen sternocleidomastoid and trapezius Ⅻ Hypoglossal nucleus Hypoglossal canal muscles of tongue

Mixed cranial nerves 混合性脑神经 V. Trigeminal nerve VII.Facial nerve IX. Glossopharyngeal nerve X. 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 Ophthalmic nerve 眼神经 (Ⅴ1, sensory) Branches leave the skull through the superior orbital fissure 眶上裂, 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:→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 nose Cerebral dura mater硬脑膜

Maxillary nerve 上颌神经 (Ⅴ2, sensory) Leave skull through foramen rotundum 圆孔 Branches Infraorbital nerve 眶下神经 Zygomatic nerve 颧神经 Superior alveolar nerve 上牙槽神经 Pterygopalatine nerve 翼腭神经

Distribution: Maxillary teeth Mucosa of nose and mouth Skin between the palpebral fissure and oral fissure. cerebral dura mater

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 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: 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 submandibular 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 end the nucleus of solitary tract孤束核. General somatic afferent fiber: fibers distribute the skin of external ear.

leaves skull through internal 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.

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(下颌下神经节), the postganglionic fibers supply submandibular and sublingual glands Branches within the facial canal

Greater petrosal nerve 岩大神经: fibers pass to pterygopalatine 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

Branches outside of facial canal Temporal branch 颞支 Zygomatic branch 颧支 Buccal branch 颊支 Marginal mandibular branch 下颌缘支 Cervical branch 颈支

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) Components of fibers 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.

Glossopharyngeal nerve (Ⅸ) Components of fibers 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.

Course: leaves the skull via jugular foramen 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.(Ⅴ3) to parotid gland

Branches 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

Pharyngeal branches Lingual branches Carotid sinus branch

Vagus nerve (Ⅹ) components of fibers 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 viscera Special visceral efferent fiber: originate from the nucleus ambiguus, to muscles of pharynx and larynx

Vagus nerve (Ⅹ) components of fibers 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.

Course Right vagus nerve Exits the skull from jugular foramen Descends in the neck in carotid sheath between internal (or common) carotid artery and internal jugular vein 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

Left vagus nerve Enter 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.

Branches in neck Superior laryngeal nerve 喉上神经 Internal branch which pierces thyrohyoid membrane to innervates mucous membrane of larynx above fissure of glottis External branch, which innervates cricothyroid Internal branch External branch Cervical cardiac branches 颈心支 descending to terminate in cardiac plexus

Branches in thorax Recurrent laryngeal nerves 喉返神经 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 muscles except cricothyroid Bronchial and esophageal branches

Anterior and posterior gastric branches Branches in abdomen Anterior and posterior gastric branches Run close to lesser curvature and innervate anterior and posterior surfaces of stomach Hepatic branches 肝支: supply liver and gallbladder 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

Nucleus of oculomotor n. Accessory nucleus of oculomotor n.

Auriculotemporal nerve Inferior alveolar nerve下牙槽神经

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 rectus Optic n. → visual sense; Ophthalmic n. →general sense of eyeball; sympathetic n. →dilator pupillae; parasympathetic n. →sphincter pupillae and ciliary m.