Cranial Nerves by rabia zulfiqar

1. CRANIAL NERVES
By : Rabia Zulfiqar (Dental Technologist)

2. Cranial Nerves

3. Cranial Nerve I: OlfactoryCranial Nerve I: Olfactory
Arises from the olfactory epithelium
• Passes through the cribriform plate of the ethmoid
bone
• Fibers run through the olfactory bulb and terminate
in the primary olfactory cortex
• Functions :sense of smell

4. Cranial Nerve II: Optic Nerve
Fibers arises from the granular
layer of ratine,and converge
at optic disc and form optic
radiation.
• Optic nerves pass through
the optic canals and
converge at the optic
chiasma.and optic tracts
ends into lateral geniculate
body, pretactal nucles,and
superior colliculus.
• From there, the optic
radiation fibers run to the
visual cortex
• Functions : impulses for
vision

5. Cranial Nerve III: Occulomotor Nerve
• Fibers extend from superior colliculus pass through
cavernous sinus and then into the superior orbital
fissure, and go to the extrinsic eye muscles.
• Functions in raising the eyelid, directing the eyeball,
constricting the iris, and controlling lens shape.

6. Cranial Nerve IV: Trochlear
• Fibers emerge from the inferior colliculus and enter the
orbits via the superior orbital fissures; innervate the
superior oblique muscle
• Primarily a motor nerve that directs the eyeball

7. Cranial Nerve V: Trigeminal
Pathway :
emerge from the anterolateral part of pons and then pass from the post.cranial
fossa to middle cranial fossa and lie at the petrous temporal bone in
meckel's cave.
Composed of three divisions:
ophthalmic (V1), maxillary (V2), and mandibular (V3)
Opthalmic division:
Frontal
supratrochlear
supraorbital
Nasocilliary:
Post.ethmoid
long cilliary
Nerve to cilliary ganglion
Infratrochlear
Ant. Ethmoid
Lacrimal : lateral part of upper eyelid

8. Maxillary Nerve :
• In Middle Cranial fossa : meningeal branches
• In pterogopalatine fossa : Ganglonic Branches
• zygomatic :
• (a) zygomaticotemporal
• (b) zygomaticofacial
• Posterior superior Alveoler
• In infraorbital Canal :
• Middle sup.alveolar
• Ant.sup. alveolar
• On face : palpebral
• labial
• Nasal

9. Mandibullar Division :
• Trunk : 1-Meningeal
• 2-Nerve to Medial pterygoid
• Anterior Division :
• Deep temporal
• Masseteric
• Lateral pterygoid
• Buccal
• Posterior Division :
• Auriculotemporal
• (a) Auricular
• (b) Superficial Temporal
• Lingual
• Inferior Alveolar
• (a) Mylohyoid
• (b) Anterior Belly of Digastric

10. Cranial Nerve V: Trigeminal
Figure V from Table 13.2

11. Cranial Nerve VI: Abducent
• Fibers emerge from the lower border of pons and then
enter into lateral wall of cavernous sinus and enter into the
orbit via the superior orbital fissure
• supply to the lateral rectus muscle of eye.

12. Cranial Nerve VII: Facial
• Fibers leave the pons, travel through the
internal acoustic meatus, and emerge
through the stylomastoid foramen to the
lateral aspect of the face
• Mixed nerve with five major branches
• Motor functions include facial expression, and
the transmittal of autonomic impulses to
lacrimal and salivary glands
• Sensory function is taste from the anterior
two-thirds of the tongue

13. Cranial Nerve VII: Facial
Figure VII from Table 13.2

14. Nuclei :
• Brachiomotor
• superior salivatory
• lacrimatory
• tractus solitarius
Branches
• within the facial canal:
• Greater petrosal nerve
• Nerve to the stapedius
• chorda tempani
• At the exit from the foramen :
• posterior Auricular
• digastric
• Stylohyoid
• Terminal branches within canal :
• Temporal
• Zygomatic
• Buccal
• Marginal Mandibular
• Cervical

15. Cranial Nerve VIII: Vestibulocochlear
• Fibers arise from the hearing and equilibrium apparatus of the inner
ear, pass through the internal acoustic meatus, and enter the
brainstem at the pons-medulla border
• Two divisions – cochlear (hearing) and vestibular (balance)
• Functions are solely sensory – equilibrium and hearing

16. Cranial Nerve IX: Glossopharyngeal
• Fibers emerge from the medulla, leave the skull via the jugular foramen, and
run to the throat
• Nerve IX is a mixed nerve with motor and sensory functions
• Motor – innervates part of the tongue and pharynx, and provides motor fibers
to the parotid salivary gland
• Sensory – fibers conduct taste and general sensory impulses from the
tongue.
Nuclei :
Nucleus Ambigus
Inferior salivatory
Tractus solitarus
Branches
Tympanic branch
Carotid branch
Pharyngeal Branch
Muscular
Tonsillar
Lingual branch

17. Cranial Nerve X: Vagus
Nuclei :
• Nucleus Ambigus
• Dorsal Nucles of Vagus
• Nucleus of tractus solitarus
• nucleus of spinal tract of trigeminal
• Branches:
• In jugular foramen,superior ganglion gives off branches:
• Meningeal
• Auricular Branches
• Branches Arising In the Neck :
• Pharyngeal
• Carotid
• superior laryngeal
• Right recurrent laryngeal
• Cardiac

18. Cranial Nerve X: Vagus
Figure X from Table 13.2
Nerve emerge from the nucleus ambigus and then enter into
the jugular foramen. after leaving the jugular foramen.it supply
the
Its sensory function is in taste.

19. Cranial Nerve XI: Accessory
• Cranial root arises from the
lower part of nucleus ambigus.
• spinal root arises from a long
spinal nucleus extending
between the segment c1-c5 .
both spinal and cranial root
pass through the jugular
foramen and unite each other
and after emerging from the
foramen cranial nucleus supply
the palate.
• spinal fiber supply the
sternocleidomastoid muscle
and trapezius muscle.

20. Cranial Nerve XII: Hypoglossal
• Fibers arise from the medulla and exit the skull via the hypoglossal canal.
• Innervates both extrinsic and intrinsic muscles of the tongue, which contribute to
swallowing and speech.
• Branches :
• meningeal branches
• Descending branch