CN VII: Facial Nerve
Overview
Roles
- Special sensory (taste) - anterior â…” of tongue
- Somatic sensory - external ear, posterior auricle (Ramsay-Hunt zone)
- Somatic motor - facial expression, eye closing
- Visceral motor (parasympathetic) - submandibular & sublingual salivary glands, lacrimal glands, nasal & palatine glands
Facial Nerve Palsy
Abnormalities
- Facial droop / weakness
- Inability to close eye
- Loss of taste
- Dry eyes / mouth
Causes of Facial Nerve Palsy
- Supranuclear
- Ischaemic stroke (lacunar or superior cerebellar artery)
- Tumour - primary / secondary
- Nuclear / Infranuclear
- Bell's palsy (idiopathic)
- Ramsay-Hunt syndrome (Herpes zoster)
- Tumour - primary / secondary
- Parotid gland pathology
- Otitis media / externa
- Skull fracture
- Guillain-Barre
- Ischaemia
- Lyme disease
- Leprosy
Motor Pathway
Cortical Centre
Primary motor cortex (precentral gyrus)
Primary motor cortex (precentral gyrus)
Facial Motor Nucleus
Pons
Pons
Foramen
Internal auditory meatus
Internal auditory meatus
Geniculate Ganglion
Division
Temporal, zygomatic, buccal, marginal mandibular and cervical branches
Temporal, zygomatic, buccal, marginal mandibular and cervical branches
Muscles
Facial expression, orbicularis oculi
Facial expression, orbicularis oculi
Special Sensory Pathway
Gustatory Cortex
Insula
Insula
Thalamus
Facial Sensory Nucleus
Pons
Pons
Foramen
Internal auditory meatus
Internal auditory meatus
Geniculate Ganglion
Chorda Tympani Nerve
Sensory and parasympathetic fibres
Sensory and parasympathetic fibres
Receptors
Anterior â…” of tongue
Anterior â…” of tongue
Parasympathetic Pathway
Visceral Nuclei
Superior salivatory & lacrimal nuclei (pons)
Superior salivatory & lacrimal nuclei (pons)
Pathway
Tegmentum, red nucleus, medial substantia nigra
Tegmentum, red nucleus, medial substantia nigra
Foramen
Internal auditory meatus
Internal auditory meatus
Geniculate Ganglion
Muscle
Lacrimal glands, salivary glands, nasal & palatine glands
Lacrimal glands, salivary glands, nasal & palatine glands
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