1. By Prof. Laila M. Aboul Mahasen Morsy
TRIGEMINAL NERVE By
Prof. Laila M. Aboul Mahasen Morsy

2. Trigeminal Nerve
It is the largest cranial nerve and contains both sensory &motor fibers.
Origin :
It leaves anterior surface
of pons by 2 roots :
1. A small motor root
2. A large sensory root.
Roots of
Trigeminal N.

3. Roots of Trigeminal Nerve
A. Sensory root fibres :are
axons of cells of the trigeminal ganglion, enter the pons .
Peripheral processes of
these cells form the 3 divisions
of trigeminal nerve :
1.Ophthalmic N .
2. Maxillary N.
3. Mandibular N.
B. Motor root : arises from
motor nucleus of trigeminal in
pons , passes below trigeminal ganglion to be distributed
with mandibular nerve .

4. Primary Function of The Trigeminal Nerve (V)
It is Mixed (sensory and motor) to face
Ophthalmic branch (sensory):
1.Orbital structures
2. Nasal cavity
3. Skin of forehead, upper eyelid,
and eyebrow
4. Part of nose
Maxillary branch (sensory):
1. Lower eyelid
2. Upper lip, gums, and teeth
3. Cheek and nose
4. Palate and part of pharynx
Mandibular branch ( Mixed ):
Sensory : lower gums, teeth, and lips
palate and part of tongue
Motor : Muscles of mastication

5. Exit from the skull of trigeminal branches
N.B. trigeminal ganglion lies at the apex of petrous temporal bone .
The 3 divisions leave the cranial cavity through :
1.Ophthalmic branch:
superior orbital fissure
2.Maxillary branch:
foramen rotundum
3. Mandibular branch:
foramen ovale .

6. Ophthalmic & maxillary nerves lie on lateral wall of cavernous sinus outside the tendinuous ring, before leaving the cranial cavity
Ophthalmic N.
Maxillary N.
Mandibular N.
Trigeminal ganglion
Cavernous sinus

7. Relations of cranial nerves with cavernous sinus

8. Ophthalmic Nerve
It is the smallest of the three divisions of the trigeminal, and arises from the upper part of the trigeminal ganglion about 2.5 cm. long, which passes forward along the lateral wall of the cavernous sinus, below the oculomotor and trochlear nerves; just before entering the orbit, through the superior orbital fissure, it divides into 3 branches : lacrimal, frontal, and nasociliary nerves e

9. Branches of ophthalmic nerve
A-Nasociliary nerve
1.Sensory root of
ciliary ganglion
2.Posterior ethmoidal n.
3. Long ciliary n.
4. Infratrochlear n.
5.Anterior ethmoidal n.
B-Lacrimal nerve
C-Frontal nerve
1. Supratrochlear n.
2. Supraorbital n.

10. Lacrimal Nerve
— branch of ophthalmic nerve.
— Its branches supply the lacrimal gland with sensory fibres.
—' It also gives a palpebral branch to the lateral part of the upper eyelid.
— It receives a communication from the zygomatic nerve through which secretory fibres pass to the lacrimal gland

11. Frontal Nerve -The highest structure in the orbit
—The largest branch of ophthalmic nerve
-The highest structure in the orbit
-Enters the orbit through the superior orbital fissure (outside the common tendinous ring)
— It runs forwards under cover of the periosteum of the roof of the orbit, above the levator palpebrae
superioris
— It divides into two branches :
Supratrochlear N. : is the medial
and smaller branch.
2. Supraorbital N.: is the lateral and larger branch (continuation of the nerve).

12. Nasociliary Nerve 1.A branch of the ophthalmic nerve
2.Enters the orbit through the superior orbital fissure
(inside the common tendinous ring)
3.Crosses above the optic nerve from lateral to medial
4.Runs along the medial wall of the orbit, between the superior oblique and medial rectus muscles
5.Terminates by dividing into :
1. Anterior ethmoidal nerve
2. Infratrochlear nerve

13. Nasociliary Nerve Branches : 1.Sensory root to the ciliary ganglion
2.Long ciliary nerves
(carry sympathetic fibers from the plexus around ICA to supply dilator pupillae muscle)
3.Posterior ethmoidal nerve
4.Anterior ethmoidal nerve
5.Infratrochlear nerve

14. Maxillary Nerve

15. Maxillary Nerve (A pure sensory nerve)
One of the 3 divisions of trigeminal nerve .
Course :
1.Leaves the cranial cavity through the foramen rotundum into the pterygopalatine fossa
2.Passes through inferior orbital fissure to continue as infraorbital nerve
*The infraorbital n. passes through infra-orbital groove and terminates in the face
Branches
From the maxillary nerve
From the infraorbital nerve
Infraorbital nerve
Ophthalmic n.
Trigeminal
ganglion
Maxillary nerve
Mandibular n.

16. Branches of maxillary N. & its infraorbital branch
Infraorbital N.
Maxillary N.

17. Branches of maxillary nerve in infratemporal fossa:
l. Meningeal branch : before leaving the skull.
2. Two roots to the sphenopalatine ganglion in the pterygopalatine fossa.
3. Zygomatic nerve : arises in the infratemporal fossa and enters the orbit through the inferior orbital fissure where it divides into : Zygomaticotemporal and Zygomaticofacial nerves.
Posterior superior alveolar nerve : arises in the infratemporal fossa and divides into anterior and posterior branches which enter the maxilla to supply the premolar and molar teeth.
*The anterior branch may be described as middle superior alveolar nerve.
5. Infraorbital nerve is the terminal branch, gives many branches:
Nerve supply to the mucosa of the maxillary air sinus .
Anterior superior alveolar nerve : which supplies the incisor and canine teeth.
3. Terminal branches in the face :
a) Palpebral : to the lower eyelid.
b) Nasal : to the side of the nose.
c) Labial : to the upper lip.

18. Maxillary N. & sphenopalatine ganglion
Greater superficial
Petrosal N.
Facial N.
Deep
petrosal
Vidian N.
N. Of pterygoid
canal

20. Zygomatic Nerve
1. Branch of the maxillary nerve of the second division of trigeminal n.
2. Enters the orbit through the inferior orbital fissure
3. Divides into : zygomatico-temporal and zygomatico-facial nerves
4. Zygomatico-temporal nerve carries parasympathetic secretory fibers from the sphenopalatine ganglion to the lacrimal gland (via its communication with the lacrimal nerve)

22. Mandibular Nerve 1. The largest division of the trigeminal nerve
2. It is a mixed nerve has a sensory root and a motor root
3. It leaves the skull through the Foramen Ovale
4. Below foramen ovale, the 2 roots unite to form the trunk of the nerve
5. Then , it divides into anterior & posterior divisions
*The anterior is mainly motor
The posterior is mainly sensory

23. Branches of the mandibular nerve
Branches of the trunk: 1.Nerve to medial pterygoid 2. Nervus spinosus Branches of Anterior Division 1. Deep temporal nerves 2. Nerve to masseter 3. Nerve to lateral pterygoid 4. Buccal N. ( sensory) Branches of Posterior Division : 1. Auriculotemporal (sensory) 2. Lingual nerve (sensory) 3. Inferior alveolar nerve ( mixed)

24. Trigeminal Nerve Branches from the trunk:
1.Nerve to medial pterygoid (motor):
supply the tensor palati and tensor tympani ms
& medial pterygoid
2. Nervus spinosus (sensory) , Passes through Foramen spinosum into the cranial cavity to supply meninges

25. Anterior Division: A.3 motor branches for muscles of mastication
1.Deep temporal nerves (temporalis ms)
2.Nerve to masseter
3.Nerve to lateral pterygoid
B.one sensory branch
Buccal nerve (sensory): supplies skin over the buccinator, and mucosal lining of buccinator m.
Deep temporal
nerves
Auriculotemporal
nerve
Inferior alveolar
nerve
Lingual
nerve
Buccal nerve

26. Posterior division: sensory branches Auriculotemporal nerve
arises by 2 roots (which embrace the middle meningeal artery) and passes backwards deep to the neck of the mandible
supplies the scalp
sensory the parotid gland and carries postganglionic parasympathetic to the
parotid gland
Deep temporal
nerves
Auriculotemporal
nerve
Inferior alveolar
nerve
2. Lingual nerve
1.Joined by the chorda tympani
2.Carries general sensations from the anterior 2/3 of the tongue
& by joining chorda tympani , it carries taste sensations from the anterior 2/3 of the tongue and preganglionic parasympathetic fibres to the submandibular and sublingual glands
Lingual
nerve
Buccal nerve

27. 3. Inferior alveolar nerve
1.Runs behind the lingual nerve to reach mandibular foramen
2. It continues through mandibular canal and exits from the mental canal as mental nerve .
Inferior alveolar
nerve
Lingual nerve
Mylohoid nerve
& vessels
Mylohoid m.

28. Inferior alveolar nerve
Mental N.
Incisive N.
N. To mylohyoid

29. Branches of inferior alveolar nerve
Branches : It supplies the teeth and gums of the lower jaw. 1.Mylohyoid branch : arise from the nerve before enter the mandibular foramen . It supplies the mylohyoid and anterior belly of diagastric muscle 2. Incisive nerve which continues forwards . It supplies the canine and incisor teeth of the lower jaw. 3-Mental nerve which comes out of the mental foramen. It supplies the skin of the chin and skin and mucous membrane of the lower lip. .