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. I Olfactory (oh)
II Optic (oh)
III Oculomotor (oh)
IV Trochlear (to)
V Trigeminal (1-3) (touch)
VI Abducens (and)
VII Facial (feel)
VIII Vestibulocochlear (very)
IX Glossopharyngeal (good)
X Vagus (velvet)
XI Accessory (ah)
XII Hypoglossal (heaven)

4. How to Remember CN I-XII
Oh! Oh! Oh! To Touch And Feel Very Good Velvet! Ah Heaven!
记忆口诀：
Ⅰ嗅、 Ⅱ视、 Ⅲ 动眼,
Ⅳ 滑、Ⅴ叉、Ⅵ 是展，
Ⅶ 面、Ⅷ 前庭蜗 、Ⅸ 舌咽，
迷、副、舌下神经全

5. 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

6. Functional Components
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

7. Classification of Cranial Nerves
Sensory cranial nerves: are composed entirely of afferent (sensory) nerve fibers bringing sensations the brain
Ⅰ Olfactory nerve
Ⅱ Optic nerve
Ⅷ Vestibulocochlear nerve
Motor cranial nerves: are composed entirely of efferent (motor) fibers
Ⅲ Oculomotor nerve
Ⅳ Trochlear nerve
Ⅵ Abducent nerve
Ⅺ Accessory nerve
Ⅻ Hypoglossal nerve
Mixed cranial nerves: possess both sensory and motor fibers---
Ⅴ Trigeminal nerve,
Ⅶ Facial nerve,
Ⅸ Glossopharyngeal nerve
Ⅹ Vagus nerve

8. Olfactory Nerve

9. Olfactory cells (SVA)→ Cribriform foramina → Olfactory bulb
Olfactory Nerve
Olfactory cells (SVA)→ Cribriform foramina → Olfactory bulb

10. Optic Nerve
Ganglion cells (SSA) → Optic canal → Lateral geniculate body

11. Vestibulocochlear Nerve
Vestibular ganglion(SSA) ↘ ↗ Vestibular nuclei
Internal acoustic meatus
Cochlear ganglion (SSA) ↗ ↘ Cochlear nuclei

12. 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

13. Motor Cranial Nerves Ⅲ Superior orbital fissure Ⅳ Ⅵ Hypoglossal canalⅫ Ⅹ
Jugular foramen Ⅺ

14. Oculomotor Nerve 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 superioris
Sphincter pupillea and ciliary muscle
Ciliary ganglion 睫状神经节: lies between optic nerve and lateral rectus
Oculomotor nerve

15. Abducent Nerve
Abducent nerve

16. Trochlear n.
Oculomotor n.
Abducent n.

18. Accessory Nerve Cranial roots Spinal roots
Originate from nucleus ambiguus
Join the spinal roots to exit the jugular foramen
Join the vagus nerve and distribute to the muscles of pharynx and larynx
Spinal roots
Originate from nucleus of accessory nerve
Ascend through the foramen magnum and exit the cranium through the jugular foramen
Innervate the sternocleidomastoid and trapezius muscles

19. Hypoglossal Nerve Nucleus of hypoglossal nerve( GSE) →
Hypoglossal canal →
Muscles of tongue
Hypoglossal nerve

20. Motor Cranial Nerves N. Nucleus of origin and axon categories
Cranial exit
Main action Ⅲ
Nucleus of oculomotor nerve (GSE)
Superior orbital fissure
Motot to superior, inferior and medial recti; inferior obliquus; levator palpebrae superioris
Accessory nucleus of oculomotor nerve (GVE)
Parasympathetic to sphincter pupillea and ciliary muscles Ⅳ
Nucleus of trochlear nerve (GSE)
Motor to superior obliquus Ⅵ
Nucleus of abducent nerve (GSE)
Motor to lateral rectus Ⅺ
Nucleus ambiguus (cranial root, SVE)
Nucleus of accessory nerve (spinal root, SVE)
Jugular foramen
Motor to sternocleidomastoid and trapezius Ⅻ
Nucleus of hypoglossal nerve( GSE)
Hypoglossal canal
Motot to muscles of tongue

21. Motor Cranial Nerves

22. Oculamotor paralysis
Abducent nerve injury

23. Mixed Cranial Nerves

24. Trigeminal Nerve (Ⅴ)三叉神经
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

25. Trigeminal Nerve (Ⅴ)三叉神经
Ophthalmic nerve 眼神经 (Ⅴ1, sensory)
Leave 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

26. Trigeminal Nerve (Ⅴ)三叉神经
Ophthalmic nerve 眼神经
Branches
Frontal nerve 额神经
Lacrimal nerve 泪腺神经
Nasociliary nerve 鼻睫神经
Distribution
Sensation from cerebral dura mater
Visual organ
Mucosa of nose
Skin above the eye and back of nose

27. Trigeminal Nerve (Ⅴ)三叉神经
Maxillary nerve 上颌神经 (Ⅴ2, sensory)
Leave skull through foramen rotundum
Branches
Infraorbital nerve 眶下神经
Superior alveolar nerve 上牙槽神经
Zygomatic nerve 颧神经
Pterygopalatine nerve 翼腭神经

28. Trigeminal Nerve (Ⅴ)三叉神经
Maxillary nerve 上颌神经
Branches
Infraorbital nerve 眶下神经
Superior alveolar nerve 上牙槽神经
Zygomatic nerve 颧神经
Pterygopalatine nerve 翼腭神经
Distribution
Sensation from cerebral dura mater
Maxillary teeth and gum
Mucosa of nose, mouth and maxillary sinus
Skin between eye and mouth

29. Trigeminal Nerve (Ⅴ)三叉神经
Mandibular nerve 下颌神经(Ⅴ3, mixed)
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

30. Trigeminal Nerve (Ⅴ)三叉神经
Mandibular nerve 下颌神经
Distribution
Sensation from cerebral dura mater
Teeth and gum of lower jaw
Mucosa of anterior 2/3 of tongue and floor of mouth
Skin of auricular and temporal regions and below the mouth
Motor to masticatory muscles, mylohyoid, and anterior belly of digastric

31. Facial Nerve (Ⅶ)面神经 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 fibers from taste buds of anterior two-thirds of tongue which cell bodies are in the geniculate ganglion and end by synapsing with cells of nucleus of solitary tract
GSA fibers from skin of external ear

33. Facial Nerve (Ⅶ)面神经 Course:
Exits the brain stem through the bulbopontine sulcus
Leaves the 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

34. Facial Nerve (Ⅶ)面神经 Branches within the facial canal
Chorda tympani 鼓索: joins lingual branch of mandibular nerve
SVA fiber to taste buds on anterior two-thirds of tongue
GVE fibers relayed in submandibular ganglion, the postganglionic fibers supply submandibular and sublingual glands

35. Facial Nerve (Ⅶ)面神经
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
Pterygopalatine ganglion

36. Facial Nerve (Ⅶ)面神经
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

37. Facial Nerve (Ⅶ)面神经 Branches outside of facial canal Temporal
Zygomatic
Buccal
Marginal mandibular
Cervical

38. Facial nerve (Ⅶ) 面神经

39. Injury to the facial nerve

40. Glossopharyngeal Nerve (Ⅸ)
Components of fibers
SVE fibers: originate from nucleus ambiguus, and supply stylopharygeus which elevates the pharynx during swallowing and talking
GVE fibers: arise from inferior salivatory nucleus and relayed in otic ganglion, the postganglionic fibers supply parotid gland
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 caudal part of nucleus of solitary tract
SVA fibers: arise from the cells of inferior ganglion, the central processes of these cells terminate in rostral part of nucleus of solitary tract, the peripheral processes supply the taste buds on posterior third of tongue
GSA fibers: The cell bodies are located in the superior ganglion. The central process carry impulse from skin of posterior surface of auricle to spinal nucleus of trigeminal n.

42. Glossopharyngeal Nerve (Ⅸ)
Course:
Exits the brain stem through the retroolivary sulcus
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，distribute to the walls of pharynx
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 carotid glomus
Others: tonsillar and stylophayngeal branches
Otic ganglion 耳神经节: situated just below foramen ovale

43. Glossopharyngeal Nerve (Ⅸ)

44. 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: The cell bodies are located in the inferior vagal ganglion. The central process carry impulse from viscera in neck, thoracic and abdominal cavity to nucleus of solitary tract
GSA fibers: The cell bodies are located in the superior vagal ganglion. The central process carry impulse from auricle, external acoustic meatus and cerebral dura mater to spinal nucleus of trigeminal n.

46. Vagus Nerve (Ⅹ)
Course
Exits the brain stem through the retroolivary sulcus
Leaves the skull from the jugular foramen
Descends in the neck in carotid sheath behind the internal (or common) carotid artery and internal jugular vein

47. Left Vagus Nerve Course
Enter thoracic inlet between left common carotid and left subclavian arteries
Crosses the left side of the aortic arch where left recurrent laryngeal nerve branches off
Passes posterior to left lung root contributing to the pulmonary plexus
Descends on the anterior surface of the esophagus and 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

48. Right Vagus Nerve Course
Travels downward anterior to the right subclavian artery and enter thoracic inlet on right side of trachea
Passes posterior to right lung root contributing to the pulmonary plexus
Then passes on to the posterior surface of esophagus and 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

49. Vagus Nerve (Ⅹ) Branches in neck
Superior laryngeal nerve 喉上神经: 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

50. Vagus Nerve (Ⅹ) Superior laryngeal nerve External branch
Internal branch
External branch

51. Vagus Nerve (Ⅹ) 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 喉下神经
Innervations: laryngeal mucosa below fissure of glottis, all laryngeal muscles except cricothyroid
Bronchial and esophageal branches

52. Vagus Nerve (Ⅹ) Branches in abdomen
Anterior and posterior gastric branches 胃前、后支
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 肝支: join hepatic plexus and then supply liver and gallbladder
Celiac branches 腹腔支: send branches to celiac plexus to be distributed with sympathetic fibers to liver, gallbladder, pancreas, spleen, kidneys, intestine as far as left colic flexure

53. 动眼、滑车、展、三眼，四神皆在上裂穿；
上颌圆孔内，下颌走卵圆；
面神经、前庭蜗内耳门，舌下神经管舌下神；
舌咽、迷走、副神经，颈静脉孔内走三神。