CN V: Trigeminal Nerve
February 15th, 2021
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)
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 sensation
Midbrain, pons, medulla, upper cervical cord
Mesencephalic nucleus: proprioception of face, orbit, mastication, tongue
Main sensory nucleus: tactile sensation
Spinal nucleus: pain and temperature sensation
Trigeminal Ganglion
V1
Ophthalmic branch
Ophthalmic branch
Foramen
Superior orbital fissure
Superior orbital fissure
Receptors
Forehead, nose, cornea, conjunctiva
Forehead, nose, cornea, conjunctiva
V2
Maxillary branch
Maxillary branch
Foramen
Foramen rotundum
Foramen rotundum
Receptors
Maxillary face, nasal mucosa, upper jaw, roof of mouth
Maxillary face, nasal mucosa, upper jaw, roof of mouth
V3
Mandibular branch
Mandibular branch
Foramen
Foramen ovale
Foramen ovale
Receptors
Mandibular face, temple, external ear, lower mouth, anterior â…” of tongue
Mandibular face, temple, external ear, lower mouth, anterior â…” of tongue
Motor Pathway
Cortical Centre
Primary motor cortex (frontal lobe)
Primary motor cortex (frontal lobe)
Trigeminal Motor Nucleus
Upper pons
Upper pons
Trigeminal Nerve
Mandibular branch (V3)
Mandibular branch (V3)
Foramen
Foramen ovale
Foramen ovale
Muscles
Masseter, temporalis, medial & lateral pterygoids
Masseter, temporalis, medial & lateral pterygoids
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