Organ of Corti

The interaction between the tectorial membrane and the cilia of the hair cells plays a crucial role in stimulating the acoustic receptors. When the Reissner's membrane vibrates, these vibrations are transmitted to the endolymph and then to the tectorial membrane. This membrane is in contact with the cilia of the hair cells, which move in response to these vibrations, generating stimulation of the nerve fibers that are in contact with the excited ciliated elements. This stimulation leads to the release of chemical mediators at the cytoneural junction and the development of an action potential in the fibers of the cochlear nerve. After passing through some intermediate stations, this stimulus ultimately reaches the cortical acoustic areas (areas 41 and 42).

In conclusion, the sound waves that enter the auditory system are first transmitted by the tympanic membrane to the chain of ossicles, which then convey them to the organ of Corti. This organ converts the vibratory energy produced by the sound stimulus into nerve impulses that travel via the eighth cranial nerve to the cortical centers, where they are processed and translated into auditory sensations. The eighth cranial nerve is composed of two distinct parts: the vestibular nerve, which carries stimuli related to the sense of balance, and the cochlear nerve, which transmits acoustic stimuli collected by the neurons of the ganglion of Corti to the cortical centers.

Damage to the organ of Corti or to the inner ear can result in a reduction in hearing ability, which is known as perceptive or sensorineural hearing loss. This can occur due to various factors, such as noise exposure, inflammatory or vascular conditions, trauma, improper use of medications, chronic diseases, acute illnesses, smoking, alcohol consumption, and poor dietary habits. These are the most common causes of cochlear damage and subsequent hearing loss.