nervous system cranial nerves trigeminal nerve facial nerve

1. The nervous system
Chapter two
Dr. Haydar Muneer Salih

3. PARTS OF NERVOUS SYSTEM
1. Central nervous system (CNS):
a. Brain:
b. Spinal cord:
2. Peripheral nervous system (PNS)
It includes those parts of nervous
system which lie outside the central
nervous system. It consists of
twelve pairs of cranial nerves, thirty
one pairs of spinal nerves

4. CRANIAL NERVES
I. Olfactory
II. Optic
III. Oculomotor
IV. Trochlear
V. Trigeminal
VI. Abducent
VII. Facial
VIII. Vestibulocochlear
IX. Glossopharyngeal
X. Vagus
XI. Accessory
XII. Hypoglossal

5. 5th cranial nerve
Trigeminal nerve

6. It is called trigeminal because it
consists of three divisions, namely:
1. Ophthalmic nerve
2. Maxillary nerve
3. Mandibular nerve
The three nerves arise from a large,
semilunar trigeminal ganglion which
lies in the trigeminal fossa on the
anterior surface of the petrous
temporal bone near its apex.

7. Attached to ventral surface of pons

8. Trigeminal fossa

10. Opthalmic Division

11. 1. Ophthalmic division
It is the smallest of the three divisions
of trigeminal nerve. It is purely
sensory and It runs forward in the
lateral wall of the cavernous sinus in
the middle cranial fossa and divides
into three branches, the lacrimal,
frontal, and nasociliary nerves, which
enter the orbital cavity through the
superior orbital fissure.

14. Branches of ophthalmic nerve
1. The frontal nerve runs forward on
the upper surface of the levator
palpebrae superioris muscle and
divides into the supraorbital and
supratrochlear nerves These nerves
leave the orbital cavity and supply
the frontal air sinus and the skin of
the forehead and the scalp

16. Branches of ophthalmic nerve
 The nasociliary nerve crosses the
optic nerve, runs forward on the
upper border of the medial rectus
muscle and continues as the
anterior ethmoid nerve
 Its gives off
Ciliary branch
Infratrochlear
Posterior ethmoid

18. Branches of ophthalmic nerve
The lacrimal nerve runs forward on the
upper border of the lateral rectus
muscle. It is joined by the
zygomaticotemporal branch of the
maxillary nerve, which contains the
parasympathetic secret motor fibers to
the lacrimal gland. The lacrimal nerve
then enters the lacrimal gland and gives
branches to the conjunctiva and the
skin of the upper eyelid.

20. Maxillary Division

21. It is the second division of trigeminal nerve.
It is also purely sensory.
The nerve leaves the middle cranial fossa
through foramen rotundum and reaches
the pterygopalatine fossa
• It enters orbit through the inferior orbital
fissure where it is called as the infraorbital
nerve, it appears on the face through the
infraorbital foramen.
• Therefore, in its course the maxillary nerve
traverses in the middle cranial fossa, the
pterygopalatine fossa and the orbit

23. Important Branches of maxillary division
1. Zygomatic nerve:
a. Zygomatico-temporal nerve
b. Zygomatico-facial nerve
2. Posterior superior alveolar
nerve:
3. Middle superior alveolar nerve:
4. Anterior superior alveolar nerve:
a. The dental branches
b. The nasal branches.

25. Important Branches of maxillary division
On the face: These are also branches of
5. infra-orbital nerve after it emerges
out from infra-orbital foramen.
6. Superior labial branches: Supply the
skin and mucous membrane of the
upper lip

27. PTERYGOPALATINE GANGLION
SPHENOPALATINE GANGLION
Is the largest peripheral ganglion of the
parasympathetic system. It serves as a
relay station for the secretomotor fibres
of the lacrimal glands and mucous
glands of the nose, palate, pharynx and
paranasal sinuses. Topographically, it is
related to the maxillary nerve, but
functionally, it is connected to the facial
nerve through greater petrosal nerve.

29. PTERYGOPALATINE GANGLION
SPHENOPALATINE GANGLION
Branches
■■ Orbital branches, which enter
the orbit through the inferior orbital
fissure
■■ Greater and lesser palatine
nerves , which supply the palate, the
tonsil, and the nasal cavity
■■ Pharyngeal branch, which
supplies the roof of the nasopharynx

31. Mandibular Division

32. This is largest of the three
divisions of the trigeminal nerve
and is the nerve of the first
branchial arch
It is formed by two roots.
1. Larger sensory root:
2. Small motor root:

33. Branches of Mandibular Nerve
From Main Trunk:
1. Nervous spinosus (meningeal
branch):
2. Nerve to medial pterygoid

35. From Anterior Division:
It gives rise to 3 motor branches
and one sensory branch.
1. Deep temporal nerves:
2. Nerve to lateral pterygoid,
3. Masseteric nerve,
4. Buccal nerve: It is the sensory
branch which supplies the skin
and mucus membrane of cheek.

37. From Posterior Division:
It gives rise to three nerves namely:
1. Auriculotemporal nerve: It is a
sensory nerve.
2. Inferior alveolar nerve: It is the
larger terminal branch of mandibular
nerve and it is a mixed nerve.
3. Lingual nerve: It is primarily
sensory nerve:

41. OTIC GANGLION
It is a parasympathetic ganglion
connected to the mandibular division
of trigeminal nerve which provides a
relay station to the secretomotor
parasympathetic fibers of the parotid
gland. Topographically, it is connected
to mandibular nerve but functionally, it
is associated with glossopharyngeal
nerve

43. 7th cranial nerve
Facial nerve

44. Facial nerve is the seventh cranial
nerve it has a motor root and sensory
root (nervus intermedius which carry
somatosensory fibers and
parasympathetic secretomotor fibers
The nerve emerges on the anterior
surface of the hindbrain between the
pons and medulla oblongata

49. Terminal branches

51. Summary