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Ch. 44 - Animal Sensory Systems
Freeman - Biological Science 7th Edition
Freeman7th EditionBiological ScienceISBN: 9783584863285Not the one you use?Change textbook
Chapter 44, Problem 1

In the human ear, how do different hair cells respond to different frequencies of sound?
a. Waves of pressure move through the fluid in the cochlea.
b. Hair cells are 'sandwiched' between membranes.
c. Receptor proteins in the stereocilia of each hair cell are different; each protein responds to a certain range of frequencies.
d. Because the basilar membrane varies in stiffness, it vibrates in certain places in response to certain frequencies.

Verified step by step guidance
1
Begin by understanding the structure of the cochlea in the human ear, which is filled with fluid and contains the basilar membrane and hair cells.
Recognize that sound waves create pressure waves that travel through the fluid in the cochlea, causing the basilar membrane to vibrate.
Learn that the basilar membrane varies in stiffness along its length, with different regions responding to different frequencies of sound. This is due to the mechanical properties of the membrane.
Understand that hair cells are positioned along the basilar membrane and are 'sandwiched' between membranes, which allows them to detect vibrations.
Explore how receptor proteins in the stereocilia of each hair cell are specialized to respond to specific frequency ranges, allowing the brain to interpret different sounds based on which hair cells are activated.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Cochlea Function

The cochlea is a spiral-shaped organ in the inner ear that plays a crucial role in hearing. It transforms sound waves into electrical signals that the brain can interpret. Waves of pressure move through the fluid in the cochlea, causing the basilar membrane to vibrate, which is essential for detecting different sound frequencies.
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Basilar Membrane

The basilar membrane is a key structure within the cochlea that varies in stiffness along its length. This variation allows it to vibrate at specific locations in response to different frequencies of sound. High frequencies cause vibrations near the base, while low frequencies affect the apex, enabling frequency discrimination.
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Stereocilia and Receptor Proteins

Stereocilia are hair-like projections on hair cells in the cochlea, crucial for sound detection. Each hair cell has receptor proteins in its stereocilia that respond to specific frequency ranges. These proteins convert mechanical vibrations into electrical signals, allowing the brain to perceive different pitches.
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