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🥸intro to psychology review

Cochlea

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

The cochlea is a spiral-shaped, fluid-filled structure located in the inner ear that is responsible for the sense of hearing. It is the primary organ involved in the transduction of sound waves into electrical signals that can be interpreted by the brain.

5 Must Know Facts For Your Next Test

  1. The cochlea is a spiral-shaped, fluid-filled structure that is approximately 35 millimeters long and makes about 2.5 turns.
  2. The cochlea is divided into three fluid-filled chambers: the scala vestibuli, the scala media, and the scala tympani.
  3. The organ of Corti, which contains the hair cells, is located on the basilar membrane within the scala media.
  4. The hair cells in the organ of Corti are responsible for converting the mechanical energy of sound vibrations into electrical signals that can be interpreted by the brain.
  5. The cochlea is innervated by the auditory nerve, which transmits the electrical signals generated by the hair cells to the brain for processing.

Review Questions

  • Describe the structure and function of the cochlea within the context of the auditory system.
    • The cochlea is a spiral-shaped, fluid-filled structure located in the inner ear that is responsible for the sense of hearing. It is divided into three chambers: the scala vestibuli, the scala media, and the scala tympani. The organ of Corti, which contains the hair cells responsible for converting sound vibrations into electrical signals, is located on the basilar membrane within the scala media. The hair cells transduce the mechanical energy of sound waves into electrical impulses that are transmitted to the brain via the auditory nerve, allowing for the perception and interpretation of sound.
  • Explain the role of the basilar membrane and the organ of Corti within the cochlea in the process of hearing.
    • The basilar membrane is a structure within the cochlea that supports the organ of Corti, which contains the hair cells responsible for converting sound vibrations into electrical signals. As sound waves enter the cochlea, they cause the basilar membrane to vibrate, which in turn causes the hair cells in the organ of Corti to bend. This bending of the hair cells triggers the opening of ion channels, leading to the generation of electrical impulses that are transmitted to the brain via the auditory nerve. The specific location of the vibration along the basilar membrane corresponds to the frequency of the sound, allowing the brain to interpret the pitch of the sound.
  • Analyze the importance of the hair cells within the organ of Corti in the overall process of hearing and how their function is critical to the transduction of sound waves into neural signals.
    • The hair cells within the organ of Corti are the key sensory receptors responsible for the transduction of sound waves into electrical signals that can be interpreted by the brain. As sound waves enter the cochlea, they cause the basilar membrane to vibrate, which in turn causes the hair cells to bend. This bending of the hair cells triggers the opening of ion channels, leading to the generation of electrical impulses that are transmitted to the brain via the auditory nerve. The hair cells are essential for converting the mechanical energy of sound vibrations into neural signals, allowing the brain to perceive and interpret the various qualities of sound, such as pitch, volume, and timbre. Without the proper functioning of the hair cells, the auditory system would be unable to effectively transduce sound waves into meaningful information that can be processed and understood by the brain.