Does facial nerve go through internal acoustic meatus?
The facial nerve enters the internal auditory meatus, passes through the petrous part of the temporal bone, and exits the skull through the stylomastoid foramen. The nerve then enters the parotid gland and breaks up into its five terminal branches: temporal, zygomatic, buccal, mandibular, and cervical.
What cranial nerve passes through the internal acoustic meatus?
The internal auditory meatus provides a passage through which the vestibulocochlear nerve (CN VIII), the facial nerve (CN VII), and the labyrinthine artery (an internal auditory branch of the anterior inferior cerebellar artery in 85% of people) can pass from inside the skull to structures of the inner ear and face.
What happens if the facial cranial nerve is damaged?
Damage to the facial nerve can result in a distorted appearance to your face. You can have difficulty making a certain facial expression or problems closing your eyes. The facial muscles will often sag or droop so your face feels stiff.
What are the effects of lesions of the facial nerve between the geniculate ganglion and the origin of the chorda tympani nerve?
Lesions between the geniculate ganglion and the origin of the chorda tympani produce the same effect, except that they spare lacrimation. If the lesion is at the stylomastoid foramen, it may result in facial paralysis only.
What does the acoustic meatus do?
The internal acoustic canal (IAC), also known as the internal auditory canal or meatus (IAM), is a bony canal within the petrous portion of the temporal bone that transmits nerves and vessels from within the posterior cranial fossa to the auditory and vestibular apparatus.
Where does the facial nerve pass through?
It emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue. The nerves typically travels from the pons through the facial canal in the temporal bone and exits the skull at the stylomastoid foramen.
Where does facial nerve exit skull?
stylomastoid foramen
Along this route, the facial nerve travels in close proximity to the eighth cranial nerve, the vestibulocochlear nerve, which is responsible for hearing and balance. The facial nerve exits the base of the skull at the stylomastoid foramen, which is an opening in the bone located near the base of the ear.
Can damaged facial nerves be repaired?
Facial nerve damage can be repaired in many cases. The success rate depends on the extent and the duration of the nerve damage. The sooner it is identified and treated appropriately, the better the prognosis.
What are the symptoms of facial nerve damage?
Facial nerve problems may result in facial muscle paralysis, weakness, or twitching of the face. Dryness of the eye or the mouth, alteration of taste on the affected side, or even excessive tearing or salivation can be seen as well.
How do you treat facial nerve damage?
There are three basic approaches to facial nerve repair: direct nerve repair, cable nerve grafting or nerve substitution. Direct nerve repair is the preferred option whenever possible and is performed by removing the diseased or affected portion of the nerve, then reconnecting the two nerve ends.
What is the facial nerve responsible for?
The facial nerve is the 7th cranial nerve and carries nerve fibers that control facial movement and expression. The facial nerve also carries nerves that are involved in taste to the anterior 2/3 of the tongue and producing tears (lacrimal gland).
Where does the internal acoustic meatus lead to?
What happens to the facial nerve in a nuclear lesion?
In nuclear or infranuclear (“peripheral”) lesions, there is a partial to complete facial paralysis with smoothing of the brow, open eye, flat nasolabial fold, and drooping of the mouth ipsilateral to the lesion.
Can a nerve lesion cause a facial palsy?
A lesion involving the nuclear or infranuclear portion of the facial nerve will produce a peripheral facial palsy. If all motor components are involved, there is complete paralysis of all facial muscles on the involved side. The brow is smooth, the eye does not close, the nasolabial fold is flat, and that side of the mouth droops.
How is the motor function of the facial nerve affected?
Only the motor function of the facial nerve is affected, therefore resulting in paralysis or severe weakness of the muscles of facial expression. There are various causes of extracranial lesions of the facial nerve: Parotid gland pathology – e.g a tumour, parotitis, surgery. Infection of the nerve – particularly by the herpes virus.
How does the facial nerve raise the hyoid bone?
Nerve to the stylohyoid muscle – Innervates the stylohyoid muscle (a suprahyoid muscle of the neck). It is responsible for raising the hyoid bone. Within the parotid gland, the facial nerve terminates by bifurcating into five motor branches. These innervate the muscles of facial expression: