The trigeminal nerve is the 5th cranial nerve and the largest sensory nerve. It has both sensory and motor functions. Sensory branches innervate the face and motor branches innervate the muscles of mastication. Anatomically, it originates from nuclei in the pons and medulla and exits the cranium through three divisions - the ophthalmic, maxillary, and mandibular nerves. Clinically, the corneal reflex tests the trigeminal nerve and inferior alveolar nerve blocks are used during some dental procedures. Examination of the trigeminal nerve involves testing its sensory and motor functions.

1. BY ; GEENA KEEKKATTIL SAM (2102008)
ANUSHKA NITIN JOSHI (2102038)
TO;DR.GAKHARIA TATIA
HUMAN BODY 3(ANATOMY)

2. INTRODUCTION
 5th cranial nerve .
 Paired
 Largest
Sensory;
 Innervate skin, mucous membranes and
sinuses of face.
Motor;
 Innervate muscles of mastication, medial
and lateral pterygoid, masseter,
temporalis

3. ANATOMICAL COURSE
 Orginates from 3 sensory nucleus and 1 motor ;
1. Mesencephalic
2. Principal sensory
3. Spinal nuclei
4. Motor nucleus
 At level of pons; sensory nuclei------sensory root,
motor nucleus----motor root
 In middle cranial fossa-sensory root expands to
trigeminal ganglion
located in the depression of temporal bone----
TRIGEMINAL CAVE
Extends from midbrain
to medulla

4. Trigeminal ganglion give rise to
 Ophthalmic and maxillary nerve exit the cranium through;
1. SUPERIOR ORBITAL FOSSA
2. FORMANE N ROTUNDUM
 Mandibular nerve exit via; FORAMEN OVALE
Opthalmic nerve V1
Maxillary nerve V2
Mandibular
nerve V3

5. OPTHALMIC NERVE
 Give rise to 3 branches;
1. Frontal
2. Lacrimal
3. Nasociliary
Parasympathetic supply ---- lacrimal gland
Innervates skin and mucous membrane of
derivatives of frontonasal prominence
derivatives

6. CLINICAL RELEVANCE
CORNEAL REFLEX
 Involuntary blinking of eyes, stimulated by tactile,
thermal or painful stimulation of cornea
 Ophthalmic nerve----afferent limb detecting stimuli
facial nerve-----efferent nerve
 ABSENCE OF CORNEAL REFLEX-DAMAGE OF
TRIGEMINAL/OPTHALMIC/FACIAL NERVE

7. MAXILARY NERVE
 14 terminal branches-innervate skin, mucous
membrane, derivatives of maxillary prominence
 Parasympathetic supply to;
1. Lacrimal gland
2. Nasal gland

8. MANDIBULAR NERVE
 4 terminal branches in infra-temporal fossa
1. Buccal nerve
2. Inferior alveolar nerve
3. Auriculotemporal nerve
4. Lingual nerve
Sensory ; mucous membrane and floor of oral cavity,
external ear, lower lip chin,2/3rd of tongue
Motor ; muscles of mastication ,suprahyoid
muscles,tensor tympani

9. INFERIOR ALEVEOLAR NERVE BLOCK
 forms the inferior dental plexus innervating lower teeth.
 In some dental procedure requiring local anaesthesia,
inf.alveolar nerve get blocked, before it form plexus

10. EXAMINATION OF TRIGEMINAL NERVE
1. TESTING SENSORY SUPPLY
ask patient to close eyes
introduce cotton wisp to areas of face suppled
by 3 divisions of this nerve
2. TESTING MOTOR SUPPLY
Ask patient to clench jaw palpate
superior to zygomatic arch feel contraction
of temporalis repeat palpating ask
the patient to open the mouth and deviate
mandible to right and left check
competence of medial and lateral pterygoid
muscles