Trigeminal Nerve (CNV)

Function

• Supplies sensory innervation to the face and scalp alongside spinal nerves from C1-C3
  • CNV3 also supplies motor to muscles of mastication (see ‘Muscles of the Face‘)
    • NB CNVII (the facial nerve) supplies motor to the mimetic muscles of the face

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Structure

• Fibres originate  from the motor and sensory/parasympathetic nucleus
  • Motor nucleus from the pons
  • Sensory/parasympathetic nucleus is diffuse – comes from throughout the brainstem

• There are three main branches that arise at the trigeminal ganglion on the sphenoid bone (middle cranial fossa)
  • CN V1 –Ophthalmic branch (sensory)
    • Passes through superior orbital fissure
    • Innervates near the eyes – cornea, most paranasal sinuses, upper and anterior nasal septum, lacrimal duct, forehead, upper eyelid

• • CN V2 –  Maxillary branch (sensory)
    • Passes through foramen rotundum
    • Innervates maxillary region – maxillary sinus, upper teeth and gum, hard palate, soft palate, lower bit of nose, posterior bit of nasal septum, lower eyelid
  • CN V3 – Mandibular branch (sensory and motor)
    • Passes through foramen ovale
    • Sensory – Innervates lower cheek and below lower lip – part of cheek, lower jaw, lower lip, floor of mouth, tongue, lower teeth and gums, proprioception from jaw muscles
    • Motor – Innervates muscles of mastication