Cranial nerves

1. Supervisor :
Dr.Rana Darwish
Prepared by :
Marah Abu Al-Dab’at 20911260
Ahlam Taweel 20911199
Anaesthesia lab.
Cranial nerves

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. 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

4. Sensory cranial nerves
N. Cranial exitMain action

Ⅰ
Olfactory nerve Cribrifom
foramina
Smell

Ⅱ
Optic nerve Optic canal Vision

Ⅷ
vestibulocochlear Internal
acoustic
meatus
Equilibrium
Hearing

5. Cranial Nerve I: Olfactory
-Origin: The olfactory mucosa of the upper part
of the nasal cavity.
The bundles of the nerve pass through openings
of the cribriform plate of the ethmoidal bone.
- End in the olfactory bulb in the anterior cranial
fossa.
-Function: carrying afferent impulses for the sense
of smell

6. Cranial Nerve I: Olfactory

9. Cranial Nerve II: Optic
•Origin :Arises from the retina of the eye
•Optic nerves pass through the optic canals
and converge at the optic chiasm
•They continue to the thalamus where they
synapse.
•From there, the optic radiation fibers run to
the visual cortex
•Function : carrying afferent impulses for
vision.

10. Cranial Nerve II: Optic

11. Cranial Nerve VIII: vestibulocochlear
•Origin : The anterior surface of the brain
between the lower border of the pon and the
medulla oblongata.
•Cross the posterior cranial fossa and enter the
internal acoustic meatus with the facial nerve.

•Two divisions – cochlear (hearing) and
vestibular (balance)
•Function : equilibrium and hearing.

12. Cranial Nerve VIII: Vestibulocochlear

13. Motor cranial nerves
N. Cranial exit Main action
Ⅲ Superior orbital fissure Motot to superior, inferior and medial
recti; inferior obliquus; levator
palpebrae superioris
Parasympathetic to sphincter pupillea
and ciliary muscl
Ⅳ Superior orbital fissure Motor to superior obliquus
Ⅵ Superior orbital fissure Motor to lateral rectus
Ⅺ Jugular foramen Motor to sternocleidomastoid and
trapezius
Ⅻ Hypoglossal canal Motot to muscles of tongue

14. Cranial Nerve III: Oculomotor
•Origin : from the anterior aspect of the midbrain.
•pass through the superior orbital fissure, and go
to the extrinsic eye muscles.
•Functions:
- raising the eyelid (levator palpebrae superioris)
- directing the eyeball ( SR, MR, IR, IO )
-constricting the iris ( Ciliary muscle )
-and controlling lens shape.

15. Cranial Nerve III: Oculomotor

16. Cranial Nerve IV: Trochlear
•Origin : from the posterior aspect of the
midbrain.
• Enter the orbits via the superior orbital
fissures.
•Innervate the superior oblique muscle
• Function :directs the eyeball downward and
laterlly – SO )

17. Cranial Nerve IV: Trochlear

18. Cranial Nerve VI: Abducens
• Origin : Between the lower border of the pon
and medulla oblongata.
•Enter the orbit via the superior orbital fissure
•Function: innervating the lateral rectus muscle
( Rotate the eyeball laterally )

19. Cranial Nerve VI: Abducens

20. Cranial Nerve XI: Accessory
•Origin : has 2 roots
cranial root : emerging from the anterior aspect of
the medulla
spinal root : arising from the superior region of the
spinal cord ( C1 - C5)
•The spinal root passes upward into the cranium via
the foramen magnum
•The accessory nerve leaves the cranium via the
jugular foramen
•Function :
•Primarily a motor nerve
–Supplies fibers to the larynx, pharynx, and soft palate
–Innervates the trapezius and sternocleidomastoid, which
move the head and neck

21. Cranial Nerve XI: Accessory

22. Cranial Nerve XII: Hypoglossal
•Fibers arise from the anterior of the upper
part of the medulla and exit the skull via the
hypoglossal canal.
•Function : Innervates both intrinsic and
extrinsic (Styloglossus, Hyoglossus,
Genioglussus ) muscles of the tongue, which
contribute to swallowing and speech.
• If damaged, difficulties in speech and swallowing;
inability to protrude tongue

23. >

24. Mixed nerves

25. Cranial Nerve IX: Glossopharyngeal
•Origin :from the Anterior surface of the medulla.
• leave the skull via the jugular foramen, and run to
the throat.
•Function :
Nerve IX is a mixed nerve with motor and sensory
functions
Motor – innervates part of the pharynx, and provides
motor fibers to the parotid salivary gland
Sensory – fibers conduct taste and general sensory
impulses from the tongue and pharynx

26. Cranial Nerve IX: Glossopharyngeal
Figure IX from Table 13.2

27. Cranial Nerve X: Vagus
•The only cranial nerve that extends beyond the head and
neck
•Origin : from the anterior surface of the medulla .
•Emerges from the skill via the jugular foramen.
Function :
The vagus is a mixed nerve
Motor :
_ Palate, Pharynx.
_ Digestive, Respiratory, Chardiovascular systms
Sensory :
_ part of the pharynx, Diaphragm, Visceral organs.

28. Cranial Nerve X: Vagus

29. Cranial Nerve VII: Facial
•Origin: Between the Medulla and pon.
•travel through the internal acoustic meatus, and
emerge through the stylomastoid foramen to the
lateral aspect of the face.
•Functions:
. Motor functions include;
–Facial expression
–Transmittal of parasympathetic impulses to lacrimal and
salivary glands (submandibular and sublingual glands).
•Sensory function is taste from taste buds of anterior two-
thirds of the tongue

30. Cranial Nerve VII: Facial

31. Motor Branches :
1- Temporal: auricular and fronto-occipitalis muscles
2- Zygomatic branch : muscles of the zygomatic arch and
orbit
(Orbicularis oculi).
3- Buccal branch : muscles in the cheek and above the
mouth
((Buccinator muscle and muscle of the upper lip)).
4. Mandibular: muscles in the region of the mandible.
5. Cervical branch : the platysma muscle

Cranial Nerve VII: Facial

32. Temporal
Zygomatic
Buccal
Mandibular
Cervical

33. •Origon : From Anterior surface of the pons by a
large sensory and a small motor roots.
• The nerve passes forward out of the posterior
cranial fossa, on reaching the middle cranial
fossa, the large sensory root expands to form the
trigemenal ganglion (( The Motor Root Is
completely separated from the sensory
ganglion)).
•The Ophthalmic, maxillary, mandibualr nerves
arise from the anterior border of the ganglion.
Cranial Nerve V: Trigeminal

35. • ophthalmic nerve :
Leaves the skull from the superior orbital foramen.
It supplies the skin of the forehead and upper
eyelid and the conjunctiva and the side of the
nose.
Branches :
1.Lacrimal.
2.Frontal : Supratruchlear, supraorbital.
3.Nasoceliary : Anterior Ethmoidal, infratruchlear
nerves.
Cranial Nerve V: Trigeminal

36. •A. Infratrochlear
B. Anterior
Ethmoid
C. Posterior
Ethmoid
D. Lacrimal
E. Supraorbital
F. Supratrochlear
G. Nasociliary
frontal

37. ophthalmic nerve

38. Maxillary nerve
•Maxillary Nerve :
_ leaves the skull from the rotundum foramen
and cross the pterygopalatin fossa to enter
the orbit through the inferior orbital fissure
- It continues as the infraorbital nerve in the
infraorbital groove and emerges on the face
through the infraorbital foramen which gives
sensory fibers to the skin of the face and the
side of the nose

40. Maxillary nerve
Branches
•Meningeal branches
•Zygomatic branche:
-Zygomaticofacial & Zygomaticotemporal that
supply the skin of face and the lateral gives
parasympathetic secretomotor fibers to the
lacrimal gland via the lacrimal nerve

42. •Posterior superior alveolar nerve :
supply the maxillary sinus & the upper moler and
adjoining part of the gum and thee cheek
• middle superior alveolar nerve :
Supply the maxillary sinus & the upper
premolar ,the gum, the cheek
• anterior superior alveolar nerve :
supplies the maxillary sinus & the upper
canine and the incisor

44. •Pterygopalatine ganglion :
is a parasympathetic ganglion which is suspended
from the maxillary nerve in the pterygopalatine fossa
_ branches :
•Orbital branches : which enter the orbit through the
inferior orbital fissure .
• greater & lesser palatine nerve : that supply the
palate , the tonsil , and the nasal cavity
• pharyngeal branch : which supply the roof of the
nasopharynx

45. •Mandibular Nerve:
-Emerge from the skull through the foramen
ovale in the greater wing of the sphenoid.
-Immediately below the foramen, the small
motor root units with the sensory root.
-The mandibular nerve divides into a small
anterior and a large posterior divisions.

47. motor root

48. •Branches from the main trunk :
A meningeal branch : enters the skull through
the foramen ovale and supplies the meninges
in the middle cranial fossa.
The Nerve to the medial pterygoid muscle.

49. •Branches from the anterior division :
the anterior division gives off 3 motor branches
and one sensory branch ( Buccal branch ).
The masseteric nerve : runs laterally to supply
the massater muscle.
The two deep temporal nerves: run upward and
enter the deep surface of the temporalis muscle.
The nerve to the lateral pterygoid muscle enters
the deep surface of the muscle.

50. •The buccal nerve (a sensory nerve ): it runs at
the level of the occlusal plane of the
mandibular molars, supplies the skin of the
cheek, and the buccal gingiva of the
mandibular molars.

52. •Branches from the posterior division:
Auriculotemporal ( Sensory ) : It turns upward
behind the temporomandibular joint, under cover of
the parotid gland; escaping from beneath the gland, it
ascends over the zygomatic arch, and divides into
superficial temporal branches.
Innervation :
gives sensory branches to the skin of the auricle, the
external auditory meatus, the tympanic membrane,
the parotid gland, the TMJ, temporal branches to the
skin of the scalp.

53. Auriculotemporal

54.  Lingual nerve :
Emerges between the lower head of the lateral
pterygoid and medial pteygoid muscle and lies
between the ramus and medial pterygoid muscle in
the in the pterygomandibular space, medial to and in
front of the inferior alveolar nerve
At the lower border of the lateral pterygoid, it is joined
with the chorda tympani nerve, and it frequently
receives a branch from the inferior alveolar nerve.
Innervation : the anterior two thirds of the tongue, the
mucous membrane of the floor of the mouth, the
lingual gingiva of the mandible.

58. •Inferior alveolar nerve :
It is made up of motor and sensory nerve fibers.
Descends on the lateral surface of the
sphenomandibular ligament, posterior and
parallel to the lingual nerve within the
pterygomandibular space.
It then enters the mandibular canal through the
mandibular foramen and runs forward below the
teeth of the lower jew.
Innervates the pulpal and osseous tissues of the
mandibular teeth , facial soft tissue anterior to
the first molar.

61. Branches of the inferior alveolar berve:
It emerges through the mental foramen to divides
into 2 terminal branches
Incisive nerve : It’s a direct extension of the
inferior alveolar nerve, continuing interiorly
within the mandibular canal.
Innervation :
Pulpal and osseous tissues of the mandibular
first premolar, canine, lateral, and central
incisors and the facial periodontal tissues of the
teeth.

62. Mental nerve :
-It exits the mandible via the mental foramen
Innervation:
It provides sensory innervation to the mucous
membranes and skin of the lower lip and chin.

65. Mylohyoid nerve :arises from the inferior
alveolar nerve just above the mandibular
foramen.
- It runs forward on the medial surface of the
body of the mandible, in the mylohyiod
groove.
Innervation : supplies the Mylohiod muscle, the
anterior belly of the digastric muscle.
- In some individuals it may supply accessory
sensory innervation to the mandible in the
premolar and molar areas.

66. N. to the Mylohyoid