Congenital sensorineural deafness most commonly involves damage to which of the following structures?

• A. Ossicles of the middle ear
• B. Eustachian tube
• C. Tympanic membrane
• D. Hair cells in the cochlea

Answer: (D)

Verified step by step guidance

1. Understand the term 'congenital sensorineural deafness': This type of deafness is caused by damage to the inner ear or the auditory nerve, and it is present from birth. Sensorineural refers to issues with sensory cells or neural pathways involved in hearing.
2. Review the anatomy of the ear: The ear is divided into three main parts—outer ear, middle ear, and inner ear. Sensorineural deafness specifically involves the inner ear or auditory nerve, not the middle or outer ear.
3. Identify the role of hair cells in the cochlea: Hair cells are specialized sensory cells located in the cochlea of the inner ear. They convert sound vibrations into electrical signals that are sent to the brain via the auditory nerve. Damage to these cells can lead to sensorineural hearing loss.
4. Eliminate incorrect options: The ossicles of the middle ear, Eustachian tube, and tympanic membrane are part of the outer and middle ear, which are involved in conducting sound but are not directly related to sensorineural deafness. Damage to these structures would cause conductive hearing loss, not sensorineural deafness.
5. Conclude that congenital sensorineural deafness most commonly involves damage to the hair cells in the cochlea, as these are the sensory cells responsible for detecting sound and converting it into neural signals.