Round window

The Round Window is a key component of the human ear. It is one of the two openings into the cochlea of the inner ear, the other being the oval window. The round window allows the fluid in the cochlea to move, which in turn ensures that the hair cells of the basilar membrane will be stimulated and auditory signals will be sent to the brain.

Anatomy

The round window is located in the middle ear, below the oval window. It is sealed by the secondary tympanic membrane, also known as the round window membrane. This membrane is highly flexible, allowing it to perform its function of permitting the movement of fluid in the cochlea.

Function

The primary function of the round window is to allow the fluid in the cochlea to move. When the stapes vibrates at the oval window in response to sound, it causes waves in the fluid of the cochlea. The round window membrane moves out when the oval window membrane moves in, and vice versa. This movement of the round window membrane allows the fluid in the cochlea to move, which in turn stimulates the hair cells of the basilar membrane.

Clinical significance

Abnormalities or damage to the round window can lead to hearing loss. For example, a condition known as round window niche obliteration can cause conductive hearing loss. In this condition, the round window niche is filled with bone or fibrous tissue, preventing the round window membrane from moving properly.

See also

• Oval window
• Cochlea
• Middle ear
• Inner ear

Round_window

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  Ear Anatomy Middle Ear
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  Right Osseous Labyrinth Interior
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  Cochlea