CN V: Trigeminal Nerve
Overview
Roles
V1 Ophthalmic Nerve
- Somatic sensory: forehead, cornea, nasal cavity, oral cavity
V2 Maxillary Nerve
- Somatic sensory: maxillary face, palate, nasal cavity, oral cavity
V3 Mandibular Nerve
- Somatic sensory: mandibular face
- Motor: muscles of mastication
Trigeminal Nerve Palsy
Abnormalities
- Decreased facial sensation
- Weak muscles of mastication
- Increased / decreased jaw jerk
- Loss of corneal reflex
Causes of Trigeminal Nerve Palsy
- Trigeminal ganglion lesion - herpes zoster, tumour
- Trigeminl (V) nerve lesion - trauma, tumour, ICA aneurysm, cavernous sinus thrombosis, SLE
Sensory Pathway
- Cortical Centre
Primary sensory cortex (parietal lobe)Sensory Nuclei
Midbrain, pons, medulla, upper cervical cord
Mesencephalic nucleus: proprioception of face, orbit, mastication, tongue
Main sensory nucleus: tactile sensation
Spinal nucleus: pain and temperature sensationTrigeminal GanglionV1
Ophthalmic branchForamen
Superior orbital fissureReceptors
Forehead, nose, cornea, conjunctivaV2
Maxillary branchForamen
Foramen rotundumReceptors
Maxillary face, nasal mucosa, upper jaw, roof of mouthV3
Mandibular branchForamen
Foramen ovaleReceptors
Mandibular face, temple, external ear, lower mouth, anterior ⅔ of tongue
Motor Pathway
- Cortical Centre
Primary motor cortex (frontal lobe)Trigeminal Motor Nucleus
Upper ponsTrigeminal Nerve
Mandibular branch (V3)Foramen
Foramen ovaleMuscles
Masseter, temporalis, medial & lateral pterygoids
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