What is the pathway of the facial nerve?

The nerves typically travels from the pons through the facial canal in the temporal bone and exits the skull at the stylomastoid foramen. It arises from the brainstem from an area posterior to the cranial nerve VI (abducens nerve) and anterior to cranial nerve VIII (vestibulocochlear nerve).

Which muscles are innervated by the facial nerve?

The facial nerve passes through the stylomastoid foramen in the skull and terminates into the zygomatic, buccal, mandibular, and cervical branches. These nerves serve the muscles of facial expression, which include the frontalis, orbicularis oculi, orbicularis oris, buccinator, and platysma muscles.

Which branch of facial nerve Innervates stapedius?

Stapedius muscle

Does the facial nerve Decussate?

It is the smallest nerve in terms of the number of axons it contains and it has the greatest intracranial length. Other than the optic nerve (cranial nerve II), it is the only cranial nerve that decussates (crosses to the other side) before innervating its target.

Are facial nerves under muscles?

The facial nerve is associated with the derivatives of the second pharyngeal arch: Motor – muscles of facial expression, posterior belly of the digastric, stylohyoid and stapedius muscles.

Where does the nerve to stapedius muscle originate?

Stapedius muscle is innervated by a small branch that arises from the facial nerve (CN VII), also known as the nerve to stapedius muscle. After branching off from the mastoid segment of facial nerve, the nerve passes posterior to the pyramidal process to innervate the stapedius muscle.

What causes the palsy of the stapedius muscle?

One of the common causes of severe forms of hyperacusis is the injury of the facial nerve distal to the geniculate ganglion. When injured, the possible outcome is the palsy of stapedius muscle that results in failure to attenuate sounds coming from the outside environment.

Where is the stapedius located in the ear?

It is located in the tympanic cavity in the middle ear, connecting the pyramidal eminence of petrous part of temporal bone to the posterior aspect of the neck of stapes. Stapedius muscle is innervated by the stapedial branch of facial nerve.

Where do sensory fibers go in the facial nerve?

The facial nerve carries both motor and sensory fibers. Motor axons innervate the muscles of facial expression and the stapedius muscle. Parasympathetic fibers go to the ganglia that supply glands in the oral cavity and the lacrimal gland.