Anatomy of Trigeminal Nerve

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

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 andtrochlear 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 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 :
1.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. 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
Nasociliary 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
Ophthalmic n.
Trigeminal
ganglion
Maxillary nerve
Mandibular n.
Infraorbital nerve
Branches
From the maxillary nerve
From the infraorbital nerve

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.
4. 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:
1. Nerve supply to the mucosa of the maxillary air sinus .
2. 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
Vidian N.
N. Of pterygoid
canal
Greater superficial
Petrosal N.
Facial N.
Deep
petrosal
Sphenopalatine
ganglion

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. 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
Mandibular Nerve

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

24. 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
Trigeminal Nerve

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
Buccal nerve
Lingual
nerve
Inferior alveolar
nerve
Auriculotemporal
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
Buccal nerve
Lingual
nerve
Inferior alveolar
nerve
Auriculotemporal
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

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.
Lingual nerve
Inferior alveolar
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.
.