The document discusses the development, anatomy, and function of three cranial nerves: the trigeminal nerve (CN V), the facial nerve (CN VII), and the vestibulocochlear nerve (CN VIII). It describes the nuclei, course, branches, and sensory/motor functions of each nerve in detail.

1. DR. DIBAKOR BHATDR. DIBAKOR BHAT
HMO, Department of NeurologyHMO, Department of Neurology
Dhaka Medical College HospitalDhaka Medical College Hospital
05.04.2014

3. DEVELOPMENT
Trigeminal nerve:
Metencephalon,
Mesencephalon
Facial nerve:
Metencephalon,
Myelencephalon
Vestibulocochlear
nerve:
Myelencephalon

4. DEVELOPMENT

5. TRIGEMINAL NERVE

6. TRIGEMINAL NERVE
Largest cranial nerve
Nuclei
1.The main sensory nucleus
2.The spinal nucleus
3.The mesencephalic nucleus
4.The motor nucleus

7. The main sensory
nucleus:
It lies in the posterior part
of the Pons, lateral to the
motor nucleus. It is
continuous below with the
spinal nucleus
The spinal nucleus:
It is continuous superiorly
with the main sensory
nucleus in the Pons and
extends inferiorly through
the whole length of the
medulla oblongata and
into the upper part of the
spinal cord as far as the
second cervical segments

8. The mesencephalic
nucleus:
It is composed of a column
of unipolar nerve cells in
the lateral part of grey
matter around the
cerebral aqueduct,
extends inferiorly into
the pons as far as the
main sensory nucleus
The motor nucleus:
It is situated in the pons
medial to the main
sensory nucleus

9. Sensory branches of the trigeminal nerve
The ophthalmic, maxillary and mandibular branches leave the skull
through three separate foramina:
superior orbital fissure,
foramen rotundum and
foramen ovale
 The ophthalmic nerve carries sensory information from the scalp and
forehead, the upper eyelid, the conjunctiva and cornea of the eye, the
nose (including the tip of the nose), the nasal mucosa, the frontal sinuses
and part of the meninges (the dura and blood vessels).
 The maxillary nerve carries sensory information from the lower eyelid
and cheek, the nares and upper lip, upper teeth and gums, nasal mucosa,
the palate and roof of pharynx, the maxillary, ethmoid and sphenoid
sinuses and part of the meninges.
 The mandibular nerve carries sensory information from the lower lip, the
lower teeth and gums, the chin and jaw (except the angle of the jaw,
which is supplied by C2-C3), part of the external ear and part of the
meninges.

11. Sensory branches of the trigeminal nerve
 Touch & Pressure terminates into main sensory nucleus
 Pain & Touch terminates into spinal nucleus
 Ophthalmic division terminates into inferior part of spinal nucleus
 Maxillary division terminates into medial part of spinal nucleus
 Mandibular division terminates into inferior part of spinal nucleus

12. Motor branches of the trigeminal nerve
 Motor branches are distributed in the mandibular nerve, originate in
motor nucleus
 The motor branches of the trigeminal nerve control the movement of
eight muscles, including the four muscles of mastication
Muscles of mastication
masseter
temporalis
medial pterygoid
lateral pterygoid
Other
tensor veli palatini
mylohyoid
anterior belly of digastric
tensor tympani
 All have bilateral cortical representation. A central lesion (e.g. stroke) is
unlikely to produce any observable deficit. However, injury to the
peripheral nerve can cause paralysis of muscles on one side of the jaw.

13. Course
The trigeminal nerve leave the anterior aspect
of the pons as a small motor root and a large
sensory root. The nerve passes forward out of
the posterior cranial fossa and rests on the
upper surface of the apex of the petrous part of
the temporal bone in the middle cranial fossa.
The large sensory root now expand to form the
crescent shaped trigeminal ganglion, which
lies within a pouch of dura mater called the
trigeminal or meckel’s cave.

15. Function
The sensory function of the trigeminal nerve
is to provide the tactile, proprioceptive and
nociceptive afferent of the face and mouth. The
posterior scalp and the neck are innervated by
C2-C3, not by the trigeminal nerve.
The motor function activates the muscles of
the mastication, the tensor tympani, tensor veli
palatini, mylohyoid, and anterior belly of the
digastric.

16. FACIAL NERVE

17. FACIAL NERVE
Facial nerve is a Mixed nerve
Nuclei
The main motor nucleus
This lies deep in the reticular formation of the
lower part of the pons. The upper part of the nucleus
that supplies the muscles of the upper part of the
face receives corticonuclear fibers from both
cerebral hemisphere. The part of the nucleus
supplies the lower part of the face receives
corticonuclear fibers only from the opposite cerebral
hemisphere.

18. The parasympathetic nuclei:
These lies posterlateral to the main motor
nucleus, they are:
1. Superior salivatory nucleus
2. Lacrimal nucleus
The sensory nucleus:
This is the upper part of the nucleus of the
tractus solitarius and lies close to the motor
nucleus.

20. Intracranial Course & Relation

21. Intracranial Course & Relation

22. Intracranial Course & Relation

23. Intracranial Course & Relation

24. Intracranial Course & Relation

25. Intracranial Course & Relation

26. Branches of VII nerve

27. Branches of VII nerve

28. Terminal Branches

29. Ganglia Associations
 Geniculate ganglia
 Submandibular ganglia
 Pterygopalatine ganglia

30. Ganglia Associations

31. Ganglia Associations

32. Function
Efferent
1. Motor control of most of the muscles of facial expression,
innervates the posterior belly of the digastric, stylohyoid and
stapedius muscle of the middle ear
2. The facial also supplies parasympathetic fibers to the
submandibular gland and sublingual glands via chorda
tympani. Parasympathetic innervation serves to increase the
flow of saliva from these glands. It also supplies
parasympathetic innervation to the nasal mucosa and the
lacrimal gland via the pterygopalatine ganglion
3. Efferent limb of the corneal reflex

33. Function
Afferent
It receives taste sensations from the anterior two-thirds of the
tongue and sends them to the nucleus of solitary tract

34. VESTIBULOCOCHLEAR
NERVE

35. Vestibular nerve nuclei
1. Lateral vestibular
nucleus
2. Superior vestibular
nucleus
3. Medial vestibular
nucleus
4. Inferior vestibular
nucleus
Cochlear nerve nuclei
1. Anterior cochlear
nuclei
2. Posterior cochlear
nuclei

36. Course
It emerges from the anterior surface of the
brain between the lower border of the pons and
medulla oblongata and enters the inner skull
via the internal acoustic meatus in the temporal
bone, along with the facial nerve.

38. Function
The vestibular nerve conducts nerve impulse
from
Utricle and saccule: position of head
Semicircular canals: movement of head
The cochlear nerve conducts nerve impulse
concerned with sound from the organ of corti