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


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
Simplified diagram of the branches of CNV.
  • 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
Distribution of CNV. Note the neck and posterior head are supplied by cervical spinal nerves. Image taken from Moore & Dalley.

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