Intracranial course and branches Fig 111
• From cerebellopontine angle, crosses posterior cranial fossa, enters internal acoustic meatus (IAM; with VIII).
• Nervus intermedius joins main root of facial nerve in IAM.
Pterygopalatine ganglion
Maxillary nerve in foramen rotundum
Eustachian tube
Canal for tensor tympani
Lingual nerve, submandibular ganglion
Maxillary nerve in foramen rotundum
Fig. 11.1 Facial nerve (intracranial).
Nervus intermedius Facial canal on medial wall of tympanic cavity
Fig. 11.1 Facial nerve (intracranial).
VII at stylomastoid foramen branchiomotor fibres from facial motor nucleus to muscles of facial expression, stapedius, etc.; §" * : parasympathetic preganglionic fibres from superior salivatory nucleus; Q—: nucleus of solitary tract receiving visceral sensory fibres, cell bodies in geniculate (sensory) ganglion; * to stapedius; stippled area represents bone.
• Geniculate ganglion is deep in IAM: this houses cell bodies of sensory fibres (no synapses) in VII. Nerve turns posteriorly into:
• Facial canal running posteriorly along medial wall of tympanic (middle ear) cavity, and gives branch to stapedius (attached to stapes);
Marginal mandibular (vulnerable here)
Fig. 11.2 Facial nerve (extracranial).
Marginal mandibular (vulnerable here)
Fig. 11.2 Facial nerve (extracranial).
• Chorda tympani given off just before VII emerges at stylomastoid foramen; this passes anteriorly across tympanic membrane into infratemporal fossa where it joins lingual nerve;
• Emerges at stylomastoid foramen.
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