Facial Nerve : Mnemonics

Course

Origin: Ponto-medullary junction (Nucleus solitarius, Facial nucleus and Superior salivatory nucleus)

Internal acoustic meatus: 7 up, Coke down

  • 7th (Facial nerve) up
  • Cochlear nerve (CN VIII) down
  • Superior and inferior vestibular nerve (CN VIII) posteriorly

Facial canal:

  • Forms Geniculate ganglion
  • Gives 3 branches: GSC
    • Greater petrosal nerve (first branch; forms nerve of pterygopalatine ganglion with Deep Petrosal Nerve)
    • Nerve to Stapedius
    • Chorda tympani (taste sensation from anterior 2/3 tongue, sublingular and submandibular gland)

After exiting skull from stylomastoid foramen:

  • 3 branches before entering the parotid gland: PDS
    • Posterior auricular nerve
    • Digastric branch (Posterior belly of digastric)
    • Stylohyoid branch
  • 5 branches within the parotid gland (most superficial structure passing through parotid): Tum Zyada Bakbak Mat Karo (innervates the muscles of facial expression)
    • Tympanic
    • Zygomatic
    • Buccal
    • Marginal mandibular
    • Cervical (least important branch – supplies platysma)

Further reading:

facial nerve anatomy
Maen K. Househ, CC BY-SA 3.0, via Wikimedia Commons

Facial nerve lesions

1. Supranuclear lesion: Contralateral lower 1/2 face paralyzed; forehead wrinkling spared (Bilateral cortical innervation)

2. Infranuclear lesion: Entire face paralyzed on same size

  • At or just above stylomastoid foramen: Bell’s palsy
  • Above origin of chorda tympani: Bell’s palsy + Reduced salivation and loss of taste from anterior 2/3 tongue
  • Above origin of nerve to stapedius: Above + Hyperacusis
  • At geniculate ganglion: Above + Reduced lacrimation


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