In mammals, the auditory hair cells are located within the spiral organ of Corti on the thin basilar membrane in the cochlea of the inner ear. They derive their name from the tufts of stereocilia called hair bundles that protrude from the apical surface of the cell into the fluid-filled cochlear duct.

Is it normal to have ear hair?

For the most part, having some ear hair (even what may look like a lot) is perfectly normal and isn't cause for worry. That said, occasionally too much ear hair can crowd and clog the ear canal.

The inner ear contains thecochlea. This is the organ that converts sound waves into neural signals. These signals are passed to the brain via the auditory nerve. Coiling around the inside of the cochlea, the organ of Corti contains the cells responsible for hearing, the hair cells.

The function of the hair cells?

It is affected by the closing mechanism of the mechanical sensory ion channels at the tips of the hair bundles. The inner hair cells transform the sound vibrations in the fluids of the cochlea into electrical signals that are then relayed via the auditory nerve to the auditory brainstem and to the auditory cortex.

Do hair cells regenerate in ears?

If hair cells are damaged in any way, we suffer permanent hearing loss or balance degeneration. New research, however, is showing that there may be a way to regenerate damaged hair cells. ... Auditory hair cells are located in the cochlea of the inner ear, and are responsible for detecting sounds.

Can ear hair cells grow back?

According to MIT News, we are each born with somewhere in the region of 15,000 hair cells per ear. When there is damage to these fine hair cells, a sensorineural hearing loss forms. Unlike hair in other areas of the body, once damaged these do not grow back.

Can ear hair cells repair themselves?

While damaged auditory hair cells can be compensated for with the use of hearing aids, there is no replacement or cure for damaged vestibular hair cells. Hair cells do not function in isolation, but need to be connected to the auditory centers of the brain through nerve fibers.

The function of Ear hair cells....

There are two types of hair cells in the organ of Corti, the inner and outer hair cells. The outer hair cells (OHC) perform an amplifying role and it is the inner hair cells (IHC) that detect the sound and transmit it to the brain via the auditory nerve.

Difference Between Inner and Outer Hair Cells

The main difference between inner and outer hair cells is that the inner hair cells convert sound vibrations from the fluid in the cochlea into electrical signals that are then transmitted via the auditory nerve to the brain whereas the outer hair cells amplify low-level sounds that enter into the fluids of the cochlea mechanically.
Inner and outer hair cells are the receptive cells found in the inner ear. They are organized in two rows along the cochlear duct. The hairs of these cells project towards the inside of the cochlear duct. Generally, outer hair cells are more numerous than inner hair cells in humans.

The Inner Hair Cells

Inner hair cells are the main type of receptive cells found in the cochlea and they are responsible for converting sound waves into nerve impulses. Generally, around 3,500 inner hair cells are present in the human cochlea at birth. The sound vibrations come through the fluid of cochlea. When converted, the nerve impulses are transmitted through the auditory nerve to the auditory brainstem and to the auditory cortex.

At the apical surface of the inner hair cells, both steriocilia and one longer steriocilia called the kinocilium are present. There are approximately 100 tiny stereocilia. The kinocilium is present at one side of the inner hair cell. Both steriocilia and kinocilium face the tectorial membranes of the cochlea. The adjacent steriocilia are connected to each other by protein filaments at the apex of the steriocilia. The associated ion channels of these filaments open in response to tension. While beating the steriocilia along with the fluid of the cochlea, the deformation of the steriocilia towards the kinocilium generates a tension on the filaments. This opens the ion channels, entering the calcium ions into the cell in order to depolarize it. Once depolarized, the hair cell releases a neurotransmitter, probably glutamate from its base into the afferent fibers of the auditory vestibular nerve. Kinocilium is also responsible for the identification of head movement apart from converting sound waves into nerve impulses. Therefore, inner hair cells also serve as a vestibular organ.

Causes of inner ear hair damage?

Cochlear Damage means that all or part of your inner ear has been hurt. Damage to the cochlea typically causes permanent hearing loss. This is called sensorineural hearing loss (SNHL). ... Thousands and thousands of tiny nerves called 'hair cells' line the inside of the snail-shaped structure, the cochlea.

The Outer Hair Cells

Outer hair cells are the other type of hair cells present in cochlea. They are arranged in the organ of corti in three rows. The sensitivity of hearing in mammals is similar to that of other vertebrates without the functioning of the outer hair cells. The sensitivity is around 50 dB. Therefore, the main function of the outer hair cells is to pre-amplify the sound waves with a low amplitude. Outer hair cells increase the sensitivity from about 200 kHz in marine mammals.

The amplification of the low-amplitude sound waves is by the electromotility. Prestin is the trasnmembrane protein specifically expressed in the lateral membrane of the outer hair cells. It contracts and elongates according to the depolarization and the hyperpolarization of the outer hair cells. This mechanical response is due to the voltage-dependent conformational changes of the prestin. The system is called the cochlear amplifier.

Similarities Between Inner and Outer Hair Cells

Inner and outer hair cells are two types of receptive cells found in the inner hair.
They occur in the organ of corti, which is situated on the basilar membrane in one of the three compartments of the cochlea.
They are organized along the cochlear duct.
Steriocilia cover the apex of the cells. A kinocilium occurs in one side of the apex.
Steriocilia and kinocilium are collectively called hairs.
The hairs of them project towards the tectorial membranes of the cochlea.
The resting membrane potential of the hair cells is -65 mV.
When depolarized, calcium ions enter into these cells, which results in the release of glutamate at the peripheral terminals of fibers of the vestibulocochlear nerve.

CONCLUSION. Research on the effects of efferent activity on hair cells has provided insight on the function and feedback control of inner ear mechanoreceptor sensory organs by the brain. ... Acoustic activation of olivocochlear fibers is used in the clinic to test the integrity of the outer hair cell function.