What are the mechanisms involved in sensorineural hearing loss?
Pathophysiology. Sensory hearing loss is caused by abnormal structure or function of the hair cells of the organ of Corti in the cochlea. Neural hearing impairments are consequent upon damage to the eighth cranial nerve (the vestibulocochlear nerve) or the auditory tracts of the brainstem.
How is sound transduced in the ear?
Sound waves entering the ear travel through the external auditory canal before striking the eardrum and causing it to vibrate. The eardrum is connected to the malleus, one of three small bones of the middle ear. Also called the hammer, it transmits sound vibrations to the incus, which passes them to the stapes.
How do hair cells transduce sound?
Sound is transmitted to the fluid of the inner ear through vibrations of the tympanic membrane, malleus, incus and stapes. Transduction, the change from mechanical energy to neural impulses, takes place in the hair cells, specifically through potassium channels at the tips of the stereocilia.
What transmits sound to the inner ear?
The eardrum vibrates. The vibrations are then passed to 3 tiny bones in the middle ear called the ossicles. The ossicles amplify the sound. They send the sound waves to the inner ear and into the fluid-filled hearing organ (cochlea).
What do semicircular canals do?
Your semicircular canals are three tiny, fluid-filled tubes in your inner ear that help you keep your balance. When your head moves around, the liquid inside the semicircular canals sloshes around and moves the tiny hairs that line each canal.
What is the basilar membrane and how does it transduce sound?
The basilar membrane travels down the middle. The motion of the oval window is transmitted to the basilar membrane causing the cilia of the hair cells to move back and forth. It is the motion of the cilia that causes transduction. Adjust the frequency and amplitude of a sound and see how the cochlea responds.