1. The Cranial Nerves
山东大学医学院 解剖教研室
李振华

2. 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

3. Functional components
General somatic afferent fibers (GSA): transmit exteroceptive and 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

4. 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

5. Sensory cranial nerves
Location of cell body and axon categories
Cranial exit
Terminal nuclei
Main action Ⅰ
Olfactory cells (SVA)
Cribrifom
foramina
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

6. Olfactory nerve
Olfactory mucosa (SVA)→ Cribriform foramina → Olfactory bulb

7. Optic nerve
Ganglion cell (SSA) → Optic canal → Lateral geniculate body

8. Vestibulocochlear nerve
Vestibular ganglion(SSA) ↘ ↗ Vestibular nuclei
Internal acoustic meatus
Cochlear ganglion (SSA) ↗ ↘ Cochlear nuclei

9. Motor cranial nerves N. Nucleus of origin and axon categories
Cranial 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)
Motor to superior obliquus Ⅵ
Nucleus of abducent nerve (GSE)
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

11. Oculomotor nerve Oculomotor nerve Components Main action－supplies
General somatic efferent fibers (GSE)
General visceral efferent fibers (GVE)
Main action－supplies
Superior, inferior and medial recti; inferior obliquus; levator palpebrae superioris
Sphincter pupillea and ciliary muscle
Ciliary ganglion: lies between optic nerve and lateral rectus
Oculomotor nerve

12. Accessory nerve
Abducent nerve

13. Hypoglossal nerve
Hypoglossal nerve

14. Oculamotor paralysis
Abducent nerve injury

15. Mixed cranial nerves

16. Trigeminal nerve Components of fibers
SVE fibers: originate from motor nucleus of trigeminal 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

18. Branches
Ophthalmic nerve 眼神经 (Ⅴ1, sensory) leave the skull through the superior orbital fissure, to enter orbital cavity
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

19. Distribution:
Sensation from cerebral dura mater
Visual organ
Mucosa of nose
Skin above the eye and back of nose

20. Maxillary nerve 上颌神经(Ⅴ2, sensory)
Leave skull through foramen rotundum
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

21. Distribution: Sensation from cerebral dura mater Maxillary teeth
Mucosa of nose and mouth
Skin between eye and mouth

22. Mandibular nerve (Ⅴ3, mixed) 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

24. Distribution: Sensation from cerebral dura mater
Teeth and gum of lower jaw
Mucosa of floor of mouth
Anterior 2/3 of tongue
Skin of auricular and temporal regions and below the mouth
Motor to masticatory muscles, mylohyoid, and anterior belly of digastric

25. Facial nerve (Ⅶ) Components of fibers
SVE fibers originate from nucleus of facial nerve, and supply facial muscles
GVE fibers derived from superior salivatory nucleus and relayed in pterygopalatine ganglion and submandibular ganglion. The postganglionic 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

27. 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

28. 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 submandibular and sublingual glands

29. Greater petrosal nerve岩大神经: GVE fibers pass to pterygopalatine ganglion 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

30. Branches outside of facial canal
Temporal
Zygomatic
Buccal
Marginal mandibular
Cervical

31. 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

32. Injury to the facial nerve

33. Glossopharyngeal nerve (Ⅸ)
Components of fibers
SVE fibers: originate from nucleus ambiguus, and supply stylopharygeus
GVE fibers: arise from inferior salivatory nucleus and ralyed in otic ganglion, the postganglionic fibers supply parotid gland
SVA fibers: arise from the cells of inferior ganglion, the central 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

35. 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: GVE fibers via tympanic and lesser petrosal nerves to otic ganglion, with postganglionic fibers via auriculotemporal (Ⅴ3) to parotid gland
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

37. Vagus nerve (Ⅹ) components of fibers
GVE fibers: originate from dorsal nucleus of vagus 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

39. 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 inlet on right side of trachea
Travels downward posterior to right brachiocephalic vein and superior vena cava
Passes posterior to right lung root
Forms posterior esophageal plexus
Forms posterior vagal trunk at esophageal hiatus where it leaves thorax and passes into abdominal cavity, then divides into posterior gastric and celiac branches

40. Left vagus nerve
Enter thoracic inlet between left common carotid 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 hiatus where it leaves thorax and passes into abdominal cavity , then divides into anterior gastric and hepatic branches

41. Cervical cardiac branches : descending to terminate in cardiac plexus
Branches in neck
Superior laryngeal nerve: passes down side of pharynx and given rise to
Internal branch, which pierces thyrohyoid membrane 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 meningeal branches

42. Superior laryngeal nerve
Internal branch
External branch

43. 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

44. Branches in abdomen Anterior and posterior gastric branches
Run close to lesser curvature and 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