Stapedius reflex

Stapedius reflex is a reflex that controls the movement of the stapedius muscle in the middle ear. It is also known as the acoustic reflex or attenuation reflex. The stapedius reflex helps to protect the ear from loud sounds.

Function

The stapedius reflex is triggered when the ear is exposed to loud sounds. The stapedius muscle contracts, which stiffens the ossicles, reducing the amount of sound that is transmitted to the cochlea. This helps to protect the inner ear from damage.

Mechanism

The stapedius reflex is controlled by the facial nerve. When a loud sound is detected, the auditory system sends a signal to the brain, which then sends a signal to the facial nerve. The facial nerve stimulates the stapedius muscle to contract, reducing the movement of the ossicles and decreasing the amount of sound that reaches the cochlea.

Clinical significance

The stapedius reflex can be tested as part of an audiological examination. If the reflex is absent or abnormal, it can indicate a problem with the auditory system, such as hearing loss or a neurological disorder. The stapedius reflex test is often used in the diagnosis of Bell's palsy, a condition that affects the facial nerve.

See also

• Acoustic reflex
• Stapedius muscle
• Facial nerve
• Audiology
• Bell's palsy