Class about 5th cranial nerve, Introduction, Nucleus, Details of Nucleus, Functional component & Clinical anatomy it is useful for Medical ,Dental UG & PG Students including Bsc & Msc Nursing Students

1. TRIGEMINAL NERVE
DR. M. MD .MUSTAFA SHARIFF
SENIOR LECTURER
SRMDC -2021

2. INTRODUCTION
• It is fifth and largest cranial nerve.
• It is mixed nerve ( sensory and motor)
SENSORY TO
 Skin of face
 Mucosa of cranial viscera
 Except base of tongue and pharynx
MOTOR TO
 Muscle of mastication
 Tensor ville palatine
 Tensor tympani
 Anterior belly of digastric
 Mylohyoid

5. TRIGEMINAL NUCLEI
• A cranial nerve nucleus is a collection of neurons (gray
matter) in the brain stem that is associated with one or
more cranial nerve.
• Axon carrying information to and from the cranial nerves
form a synapse first at these nuclei.
• Lesion occurring at the nuclei can lead to effects
resembling those seen by the severing of nerves they are
associated with.

7. SENSORY NUCLEI
MESENCEPHALIC NUCLEUS
• Cell body of Pseudounipolar neuron
• Relay proprioception from muscle of mastication,
• Extra ocular muscle,
• Facial muscle
• Situated in midbrain just lateral to aqueduct

8. PRINCIPAL SENSORY NUCLEUS.
• Lies in pons lateral to motor
nucleus
• Relays touch sensation
SPINAL NUCLEUS
• Extends from caudal end of
principal sensory nucleus in
pons to 2nd or 3rd spinal
segment
• It relays pain and
temperature

9. MOTOR NUCLEUS
• Innervates muscles of mastication and tensor tympani and
tensor palatini
• Derived from first branchial arch
• Located in pons medial to principal sensory nucleus

11. FUNCTIONAL COMPONENT
SPECIAL VISCERAL EFFERENT (SVE):
• Fibers arise from motor nucleus and supply the muscle s
derived from the first pharyngeal arch mesoderm.
 Muscle of mastication
 Tensor ville palatine
 Tensor tympani
 Anterior belly of digastric
 Mylohyoid

12. GENERAL SOMATIC AFFERENT (GSA):
• GSA fibers are divided into two groups.
• Fibers carrying exteroceptive sensation from skin of the
face and mucous membrane of the mouth and nose.
• The cell bodies of these neurons lie in the trigeminal
ganglion.
• Most of the central processes of these neurons bifurcate,
the ascending branches terminate in the chief sensory
nucleus whereas descending branches end in the spinal
nucleus.

13. • Fibers carrying proprioceptive sensation from muscles of
mastication, temporomandibular joint, teeth and tongue.
• The cell bodies of these neurons lie In the Mesencephalic
nucleus.
• The peripheral processes of nerve cells located in the
trigeminal ganglion and Mesencephalic nucleus are
arranged into three division of trigeminal nerve.
• OPHTHALMIC -GSA FIBERS
• MAXILLARY -GSA FIBERS
• MANDIBULAR -GSA AND SVE FIBERS

15. COURSE AND DISTRIBUTION
• Both motor and sensory root are attached ventrally to
junction of pons and middle cerebellar peduncle with
motor root lying ventro medially to the sensory root.
• Pass anteriorly in middle cranial fossa to lie below
tentorium cerebelli in cavum trigeminale , here motor root
lies inferior to sensory root.

16. • Sensory root connected to postro medial concave border of
the trigeminal ganglion.
• Convex antrolateral margin of the ganglion gives
attachment to the 3 division of the trigeminal nerve.
• Motor root turns further inferior with sensory component
of V3 to emerge out of foramen ovale as mandibular nerve.
• Ophthalmic and maxillary division emerges through
superior orbital fissure and foramen rotundum.

21. CLINICAL ANATOMY
• Lesion of trigeminal nerve present following clinical feature.
• Loss of general sensation from face and mucous membrane
of oral and nasal cavities.
• Loss of corneal reflex
• Paralysis of muscles of mastication.
• Jaw deviated to the side of lesion due to unopposed action
of lateral pterygoid muscle.

22. • HYPOACUSIS ( partial deafness to low pitched sounds due
to paralysis of tensor tympani muscle).
TRIGEMINAL NEURALGIA (TIC DOULOUREUX)
• Is paroxysmal sever pain of sudden onset and short
duration in the area of cutaneous distribution of one or
more of the division of the trigeminal nerve, usually
affecting the 2nd and 3rd division.