International Licensing Examination (ILE) Practice Test

What is the function of the cochlear duct in the auditory system?

1. Sensory organ for balance

2. Sensory organ for hearing

3. Conduction of sound waves

4. Protection against loud sounds

The correct answer is: Sensory organ for hearing

The cochlear duct, also known as the scala media, plays a crucial role in the auditory system as the sensory organ for hearing. It is located within the cochlea of the inner ear and contains the organ of Corti, which houses the hair cells that are essential for the transduction of sound vibrations into electrical signals that the brain can interpret. When sound waves enter the cochlea, they cause the fluid within the cochlear duct to move. This movement stimulates the hair cells situated in the organ of Corti, leading to the generation of nerve impulses. These impulses are then transmitted to the auditory nerve and subsequently to the brain, where they are perceived as sound. Therefore, the cochlear duct's primary function is to facilitate the process of hearing by enabling the detection and interpretation of sound stimuli. In contrast, the other options refer to different functions or structures related to auditory and vestibular systems. For example, the sensory organ for balance refers to the vestibular system, which includes structures like the semicircular canals and otolith organs. Sound wave conduction is mainly attributed to the outer and middle ear structures, while protection against loud sounds involves mechanisms like the acoustic reflex.