What does the organ of Corti within the cochlea contain?

The organ of Corti, situated within the cochlea of the inner ear, is crucial for the process of hearing. It contains hair cells equipped with stereocilia, which are the sensory receptors for sound. When sound waves enter the cochlea, they cause fluid movement that displaces the hair cells. This displacement bends the stereocilia, triggering an electrochemical response that sends nerve signals to the brain. This is how sound is perceived.

The significance of the hair cells and their stereocilia cannot be overstated; they transform mechanical sound vibrations into neural signals that the brain interprets as sound. This function is essential to the auditory system, making the presence of hair cells in the organ of Corti fundamentally important for hearing.

The other options refer to components associated with the ear but do not pertain specifically to the organ of Corti or its primary function in hearing. While protective membranes and nerve endings for hearing are important for overall auditory function, they are not contained within the organ of Corti itself. Similarly, fluid for balance pertains to other structures within the ear, such as the vestibular system, rather than the cochlea and its organ of Corti.