the cranial nerves shandong university liu zhiyu
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The Cranial Nerves SHANDONG UNIVERSITY Liu Zhiyu
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
Fiber components of cranial n.
General somatic afferent(sensory) fibers 一 : transmit exteroceptive and proprioceptive impulses from head and face to somatic sensory nuclei of the brain stem;
Special somatic afferent (sensory) fibers transmit sensory impulses from special sense organs of vision, equilibrium and hearing to the brain ;
Fiber components of cranial n.
General visceral afferent (sensory) fibers transmit interoceptive impulses from the viscera to the visceral sensory nuclei-nucleus of solitery tract;
Special visceral afferent (sensory) fibers transmit sensory impulses from special sense organs of smell and taste to the brain;
Fiber components of cranial n.
General somatic afferent (motor) fibers : arises from the General somatic motor nuclei and innervate skeletal muscles of eye and tongue.
Special visceral afferent (motor) fibers : arises from the Special visceral motor nuclei in the brain and to skeletal muscles derived from gill arches () of embryo : such as the m. of mastication, facial expression and swallowing.
Fiber components of cranial n.
General visceral afferent (motor) fibers : arise from the general visceral motor nuclei and relayed in parasympathetic ganglions,e postganglionic fibers supply cardiac muscles , smooth muscles and glands.
Classification of cranial nerves
Sensory cranial nerves : contain only sensory fibers
Ⅰ. Olfactory nerve
Ⅱ. Optic nerve
Ⅷ. Vestibulocochlear nerve
Classification of cranial nerves
Motor cranial nerves : 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 : contain both sensory and motor fibers
Ⅴ. Trigeminal nerve
Ⅶ. Facial nerve
Ⅸ. Glossopharyngeal nerve
Ⅹ. Vagus nerve
Sensory cranial nerves
I . Olfactory nerve II. Optic nerveVIII.Vestibulocochlear nerve
Olfactory nerve
Olfactory cell → Olfactory nerve → Cribriform foramina
→ Olfactory bulb
Olfactory nerve
Function: conduct the smell
Optic nerve
Ganglion cell of retina → Optic nerve → Optic canal →
optic chiasma→optic tract → lateral geniculate body.
Vestibulocochlear nerve
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
Motor cranial nerves
III.Oculomotor nerve
IV. trochlear nerve V. VI. Abducent nerve
XI. accessory nerve
XII. hypoglossal nerve
Oculomotor nerve
supplies : Superior, inferior and medial recti; inferior obliquus; levator palpebrae superioris
Sphincter pupillae and ciliary muscleNucleus of oculomotor n.
Accessory nucleus of oculomotor n.
ComponentsGeneral somatic motor ( efferent ) fiber arises from nucleus occulomotorGeneral visceral motor ( efferent ) fiber arises from accessory nucleus of Ⅲ
Oculomotor nerve
Oculomotor nerve
Course:
•Leave the brain at the interpeduncular fossa;
•Pass through the lateral wall of cavernous sinus
•Via superior orbital fissure enter the orbita
Oculamotor paralysis
The injury of the oculomotor n. may lead to:
Droping of the upper eyelid;
lateral strabismus ;
Dilation of the pupil;
The pupillary reflexes disappear
trochlear nerve
Trochlear n. arises from the nucleus of trochlear nerve,
and pass through the superior orbital fissure to supply the superior obliquus
Abducent nerve
abducent n. arises from the nucleus of abducent nerve, and pass through the superior orbital fissure to supply the lateral rectus
Accessory nerve
Accessory nerve
Cranial root : arises from nucleus ambiguus;Spinal root arises from the accessory nucleus pass through jugular foramen,and supplies 2 muscles
sternocleidomastoid
trapezius
Hypoglossal nerve
Hypoglossal nerve
Nucleus of hypoglossal nerve
Hypoglossal canal
Function of Cranial Nerve 12
supplies the intrinsic and extrinsic muscles of the Tongue genioglossus
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
Nucleus of oculomotorSuperior orbital fissure
superior, inferior and medial recti; inferior obliquus; levator palpebrae superioris
Accessory nucleus of oculomotor (Parasympathetic )
sphincter pupillea and ciliary muscl
Ⅳ Nucleus of trochlear nerve
Superior orbital fissure
superior obliquus
Ⅵ Nucleus of abducent nerve
Superior orbital fissure
lateral rectus
ⅪNucleus of accessory nerve
Jugular foramen sternocleidomastoid and trapezius
ⅫNucleus of hypoglossal nerve
Hypoglossal canal muscles of tongue
Mixed cranial nerves
V. Trigeminal nerveVII.Facial nerveIX. Glossopharyngeal nerveX. Vagus nerve
Trigeminal nerve
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 : Supratrochlear nerve
Supraorbital nerve
Branches
Ophthalmic nerve (Ⅴ1, sensory)
leave the skull through the superior
orbital fissure, to enter orbital cavity
Lacrimal nerve :→lacrimal gland Nasociliary nerve ; → eyeball
Distribution:
Visual organ Part of mucosa of nose Skin above the palpebral fisure and back of nose cerebral dura mater
Infraorbital nerve Zygomatic nerve Superior alveolar ner
ve Pterygopalatine nerve
Maxillary nerve ( 2, sensory)Ⅴ
Leave skull through foramen rotundum
Branches
Distribution:
Maxillary teeth
Mucosa of nose and mouth
Skin between the palpebral fissure and oral fissure.
cerebral dura mater
Auriculotemporal nerve Buccal nerve Lingual nerve Inferior alveolar nerve
Nerve of masticatory muscles
Mandibular nerve (Ⅴ3, mixed)
Leave the skull through the foramen ovale 卵圆孔 to enter the infratemporal fossa
Branches
Distribution:
cerebral dura mater;
Mandibular teeth and gum;
Mucosa of floor of mouth
Anterior 2/3 of tongue;
Skin of auricular and temporal regions and below the oral fissure;
masticatory muscles, mylohyoid, and anterior belly of digastric m.
Facial nerve (Ⅶ)
Components of fibers
Special visceral efferent fiber: fibers originate from nucle
us of facial nerve, and supply facial muscles.
General visceral efferent fiber: fibers arise from superior
salivatory nucleus and relayed in pterygopalatine gangli
on and submandibular ganglion. The postganglionic fibe
rs supply lacrimal, submandibular and sublingual glands.
Facial nerve (Ⅶ)
Components of fibers.
Special visceral afferent fiber: fiber from taste buds of ant
erior 2/3 of tongue which cell bodies are in the geniculate g
anglion of the facial nerve and end the nucleus of solita
ry tract.
General somatic afferent fiber: fibers distribute the skin of
external ear.
Course: leaves skull through internal acoustic meatus, facial canal and stylomastoid foramen, it then enters parotid gland where it divides into five Branches which supply facial Muscles.
Chorda tympani : joins lingual branch of mandibular nerve
To taste buds on anterior two-thirds of tongue.
Relayed in submandibular ganglionthe postganglionic fibers sup
ply submandibular and sublingual glands
Branches within the facial canal
Greater petrosal nerve : fibers pass to pterygopalatine gangli
on and the postganglionic fibers through the zygomatic and lacrim
al nerves to lacrimal gland
Stapedial nerve to stapedius
Temporal branch
Zygomatic branch
Buccal branch
Marginal mandibular branch
Cervical branch
Branches outside of facial canal
Pterygopalatine ganglion : lies in pterygopalatine fossa under maxillary nerve
Submandibular ganglion : lies between lingual nerve and submandibular gland
Injury to the facial nerve
?2. How to distinguish the supranuclear paralysis and infranuclear paralysis
1. Is this paralysis belong to supranuclear paralysis and infranuclear paralysis
Glossopharyngeal nerve ( )Ⅸ
Special visceral efferent fiber: originate from nucleus ambiguus, and supply stylopharygeus.
general visceral efferent fiber: arise from inferior salivatory nucleus and ralyed in otic ganglion, the postganglionic fibers supply parotid gland.
Special visceral afferent fiber: transmit the taste of posterior third of tongue to the nucleus of solitary tract.
Components of fibers
Glossopharyngeal nerve ( )Ⅸ
general visceral afferent fiber: transmit the visceral sensation from mucosa of posterior third of tongue, pharynx, auditory tube and tympanic cavity, carotid sinus and glomus, to the nucleus of solitary tract.
general somatic afferent fiber: conduct the sensation from skin of posterior surface of auricle.
Components of fibers
Branches
Lingual branches : to taste buds and mucosa of posterior third of tongue
Pharyngeal branches : take part in forming the pharyngeal plexus
Tympanic nerve : → tympanic cavity and auditory tube, and its general visceral motor fibers via lesser petrosal nerves to end the otic ganglion, the postganglionic fibers via auriculotemporal n.( 3) to Ⅴ parotid gland
Course: leaves the skull via jugular foramen
Carotid sinus branch : →carotid sinus and glomus
Others: tonsillar and stylophayngeal branches
Otic ganglion : 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, 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
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 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
Internal branch
Cervical cardiac branches descending to terminate in cardiac plexus
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 cric
othyroid 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 : supply liver and gallbladder
Nucleus of oculomotor n.
Accessory nucleus of oculomotor n.
Inferior alveolar nerve
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.
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