What happens if the stapedius is damaged?
If there is damage to the nerve to stapedius, wider oscillations of the stapes will occur resulting in hyperacusis—sounds being perceived as extremely loud, more so than they actually are to a person without damage to this nerve.
What is the stapes innervated by?
the VII nerve
The stapedius muscle is attached to the stapes; it is innervated by a branch of the VII nerve. The tensor tympani is attached to the malleus; it is innervated by a branch of the Vth cranial nerve. The action of both muscles is to decrease sound transmission through the middle ear.
What’s the cause of Bells Palsy?
The cause of Bell’s palsy is unknown but is thought to be caused by inflammation affecting the body’s immune system. It is associated with other conditions such as diabetes. Symptoms of facial weakness or paralysis get worse over the first few days and start to improve in about 2 weeks.
What Innervates the stapedius muscle?
The branches of the facial nerve: The nerve to stapedius innervates the stapedius muscle. The communicating branch with the tympanic plexus runs in the mucous membrane of the tympanic cavity and ramifies in the tympanic plexus of the glossopharyngeal nerve.
What does the stapedius muscle do?
Stapedius muscle is termed to be the smallest skeletal muscle in human body, which has a major role in otology. Stapedius muscle is one of the intratympanic muscles for the regulation of sound.
What nerve Innervates stapedius muscle?
the facial nerve
The branches of the facial nerve: The nerve to stapedius innervates the stapedius muscle.
What does the stapedius nerve do?
Stapedius muscle is innervated by the stapedial branch of facial nerve. These autonomic fibers enable the muscle to be involved in the auditory middle ear reflex, having a crucial role in protecting the auditory system from damage.
What do the 7th and 8th cranial nerves do?
The vestibulo-cochlear nerve enters the internal auditory meatus, dividing as it does so into the vestibular and cochlear nerves. The vestibular nerve passes through this opening into the inner ear, the cochlear nerve passes through this one. The two nerves transmit our senses of balance and hearing respectively.
What does the 7th cranial nerve innervate?
Their function is to innervate the muscles of facial expression, the stapedius muscle, the stylohyoid muscle, and the posterior belly of the digastric muscle.
What 4 muscles are affected by Bell’s palsy?
These nerves serve the muscles of facial expression, which include the frontalis, orbicularis oculi, orbicularis oris, buccinator, and platysma muscles.
What nerve innervates the stapedius?
It arises from a prominence in the tympanic cavity at the posterior aspect called the pyramidal eminence. It inserts into the neck of the stapes. The nerve to stapedius arises opposite the pyramidal eminence from the facial nerve, and it passes through this canal to innervate the stapedius.
Which cranial nerve causes the stapedius reflex?
The stapedius reflex is made possible by the facial nerve, which is the seventh cranial nerve (CN VII). When loud noises enter the ear, the brain sends electrical signals through the facial nerve telling the stapedius muscle to contract in order to stabilize the stapes bone.
Where is the stapedius muscle located?
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.
What is the function of the nerve in the arm?
The arm is the region of the upper extremity extending between the shoulder and elbow joints. The nerves found within the arm are terminal branches of the brachial plexus and serve to innervate muscles of the upper extremity and transmit sensory information to the higher processing centers of the brain.[1]