The trigeminal nerve is the largest cranial nerve. It has both sensory and motor functions. Sensory fibers carry sensations from the face and head to nuclei in the pons and medulla. Motor fibers innervate muscles of mastication. The trigeminal nerve divides into three main branches - the ophthalmic, maxillary, and mandibular nerves - which further branch to innervate regions of the face, scalp and oral cavity.

2. The Trigeminal Nerve
Presented by : Anam khan

3. Trigeminal Nerve (Cranial
Nerve V)
• It is the largest cranial
nerve and contains both
sensory and motor fibers.
• It is sensory to greater
part of head and motor to
several muscles including
muscles of mastication.

4. Trigeminal
Nerve
Nuclei
• It has four nuclei:
(1) Main sensory
nucleus.
(2) Spinal nucleus.
(3)Mesencephalic
nucleus.
(4) Motor
nucleus.

5. • Main sensory nucleus lies
in posterior part of Pons
lateral to the motor
nucleus.
• Spinal nucleus continuous
superiorly with main
sensory nucleus and
extends inferiorly through
medulla oblongata and into
upper part of spinal cord as
far as second cervical
segment.

6. • Mesencephalic Nucleus
composed of unipolar cells
situated in lateral part of
gray matter around
cerebral aqueduct.
• It extends inferiorly into
pons as far as main
sensory nucleus.
• Motor nucleus is situated
in pons medial to main
sensory nucleus.

7. Course of the
Trigeminal Nerve
• Trigeminal nerve leaves
anterior aspect of Pons as
a small motor root and a
large sensory root.
• It passes forward out of
posterior cranial fossa and
rests on apex of petrous
bone in middle cranial
fossa here sensory root
expands to form trigeminal
ganglion.

9. 3 Main Divisions
•Ophthalmic, maxillary, and
mandibular nerves arise
from the anterior border of
ganglion.

12. • Ophthalmic nerve (V1)
contains only sensory
fibers leaves skull through
superior orbital fissure to
orbital cavity.

13. It is the superior division of the V
nerve & is the smallest.
Leaves the cranium and enters the
orbit through superior orbital
fissure.
It is wholly sensory.

14.  It has 3 branches. All 3 of them pass through the
sup. orbital fissure into the orbit. They are;
1.Lacrimal nerve
2.Frontal nerve
3.Nasocilliary nerve

16. 1. Lacrimal nerve
• It is the smallest.
• It supplies the lacrimal gland & the conjuntiva.
• It pireces the orbital septum and ends in the skin of
the upper eyelid.

17. 2) Frontal nerve:
It is the largest branch & appears to be the direct
continuation of the ophthalmic division. It enters the orbit
through the SOF divides into 2 branches.
-The supra orbital branch: It is larger & more laterally placed. It
supplies the skin of the forehead & scalp as far back as the
vertex. It also supplies the mucous membrane of the frontal
sinus & pericranium
-The supra trochlear branch: It is smaller & more medially
placed. It curves upward on the forehead , close to the
bone. It supplies the skin of the upper eyelid & lower part of
the forehead.

18. 3) Nasocilliary nerve: It is intermediate in size & runs
more deeply. Its branches are divided as following;
Branches in the Orbit
Branches in the Nasal cavity
Branches on the face
(I) Branches in the Orbit:
-Long root of the cilliary ganglion (supplies the eyeball)
-Long ciliary nerve (Supplies the Iris & Cornea)
-Posterior ethmoidal nerve(supplies to the mucous membrane
lining of the Post. Etmoidal & Sphenoidal paranasal air cells)
-Anterior ethmoidal nerve(: It supplies to the Ant.ethmoidal & frontal paranasal
air cells)

20. (2) Branches in the Nasal CAvity
supply the mucous membrane ofthe nasal
cavity.
(3) Terminal Branches on face
the skin of the medial parts of
both eyelids, the lacrimal sac. They also supply
skin on the bridge of the nose.

22. • Maxillary nerve (V2)
This is the second & intermediate division of the trigeminal
nerve.
It is wholly sensory.
• leaves the skull through foramen rotundum. It
crosses the upper part of the pterygopalatine fossa,
inclines laterally on the posterior part of the orbital
process of the maxilla & enters the orbit through the
inferior orbital fissure.It is now termed as the infra
orbital nerve

24. The branches of the maxillary nerve can be divided into the following 4 groups:
1) In the cranium:
-Meningeal (duramater of the anterior & middle cranial fossae.)
2) In the pterygopalatine fossa:
- Ganglionic branches(sensory fibres to the orbital periosteum & mucous
membrane of the nose, palate & pharynx)
-Zygomatic nerve( Zygomaticofacial :supplies the skin over the zygomatic bone,
Zygomaticotemporal: supplies the skin over the anterior temporal fossa
region.)
-Post.superior alveolar
3) In the infra orbital canal:
Middle sup. Alveolar nerve(supply the maxillary premolars & mesiobuccal root
of the first molar teeth )
Anterior superior/ Greater alveolar(canine & incisors, mucous membrane of the
anterior part of the lateral wall & floor of the nasal cavity)

25. 4) On the face:
- Palpebral(supplying the skin over the lower
eyelid& lateral angle of the eye )
-Nasal(skin of the nose & tip of the nasal
septum)
-superior labial (the skin over the anterior part
of the cheek & upper lip including the mucous
membrane & labial glands)

26. Sphenopalatine/pterygopalatine
ganglion
The branches of the Pterygopalatine ganglion are:-
I. Orbital branches:
II.Palatine branches:
1.Anterior/greater palatine
2.Middle palatine
3.Posterior palatine
III.Nasal branches:
1.Posterior superior lateral
2.Nasopalatine/Sphenopalatine
IV.Pharyngeal branch:

28. Mandibular nerve (V3)
• contains both sensory and motor fibers and leaves skull
through foramen ovale.
• It is the third & largest division of the trigeminal
nerve.It is made up of 2 roots:
• a large sensory root which proceeds from the lateral part of
the trigeminal ganglion & almost immediately emerges out
through the foramen ovale
• & a small motor root which passes below the ganglion, &
unites with the sensory root just outside the
foramen.
• The sensory fibers to skin of face from each division
supply a distinct zone with little or no overlap of
dermatomes .

30. The braches of the Mandibular nerve:-
I. Branches of the undivided nerve.
i. Meningeal branch/nervus spinosus. (supply
the dura of the middle & anterior cranial
fossae.)
ii. Nerve to the medial pterygoid (deep
surface of the muscle.)

31. II. Branches of the divided nerve:
(A) Anterior division:
1.Buccal nerve
2.Massetric nerve
3.Deep temporal nerve
4.Nerve to the lateral pterygoid.

32. B) Posterior division:
• 1.Auriculotemporal
1. Parotid branches-----secretomotor, vasomotor.
2. Articular branches--- to the TMJ.
3. Auricular branches---to the skin of the helix & tragus.
4. Meatal branches----- Meatus of the tymphanic
membrane
5. Terminal branches----Scalp over the temporal region
• 2.Lingual nerve It gives off sensory fibres to the tonsil &
the mucous membrane of the posterior part of the
oral cavity.

33. 3.Inferior alveolar nerve
• Branches of the nerve :-
1. Mental nerve: it supplies to the skin of the chin & the
mucous membrane as well as the skin of the lower lip.
2. Incisive branch: supplies the canine & incisors.
3. Mylohyoid nerve: it is given of before the nerve enters
the canal & contains both sensory & motor
fibressupplying the mylohyoid muscle as well as the
anterior belly of the digastric.
•

35. Sensory Components of the
Trigeminal Nerve
• Pain, temperature, touch, and
pressure from skin of face and
mucous membranes travel along
axons whose cell bodies are
situated in the trigeminal
ganglion.
• The central processes of these
cells form sensory root of
trigeminal nerve.
• About half the fibers divide into
ascending and descending
branches when they enter the
pons.
• The remainder ascend or descend
without division.

36. • The ascending branches
terminate in main
sensory nucleus, and
descending branches
terminate in spinal
nucleus.
• Touch and pressure are
conveyed by nerve
fibers that terminate in
the main sensory
nucleus.
• Pain and temperature
pass to spinal nucleus.

37. • Proprioceptive impulses from
muscles of mastication and from
facial and extraocular muscles
are carried by fibers of unipolar
cells of the mesencephalic
nucleus that have bypassed
trigeminal ganglion.
• Axons of the neurons in the
main sensory and spinal nuclei
and central processes of cells in
mesencephalic nucleus now
cross median plane and ascend
as trigeminal lemniscus to
terminate on nerve cells of
ventral posteromedial nucleus of
the thalamus.
• Axons of these cells now travel
through genu internal capsule to
postcentral gyrus (areas 3, 1, and
2) of the cerebral cortex.

38. Motor Component of the
Trigeminal Nerve
• Motor nucleus receives
corticonuclear fibers from both
cerebral hemispheres.
• It also receives fibers from
reticular formation, red
nucleus, tectum, and medial
longitudinal fasciculus.
• In addition, it receives fibers
from the mesencephalic
nucleus, thereby forming a
monosynaptic reflex arc.
• Cells of motor nucleus give rise
to axons that form motor root.
• Motor nucleus supplies
muscles of mastication, tensor
tympani, tensor veli palatini,
mylohyoid and anterior belly
of digastric muscle.