Tympanic duct: Difference between revisions

Revision as of 23:55, 9 February 2025

Part of the inner ear involved in hearing

Tympanic duct

The tympanic duct, also known as the scala tympani, is one of the three fluid-filled passages in the cochlea of the inner ear. It plays a crucial role in the process of hearing by transmitting sound vibrations from the oval window to the round window.

Anatomy

The tympanic duct is located in the cochlea, which is a spiral-shaped organ within the osseous labyrinth of the inner ear. It is situated below the cochlear duct (scala media) and is separated from it by the basilar membrane. The tympanic duct is filled with a fluid called perilymph, which is similar in composition to cerebrospinal fluid.

Cross-section of the cochlea, showing the tympanic duct (scala tympani).

Function

The primary function of the tympanic duct is to transmit sound vibrations. When sound waves enter the ear, they cause the tympanic membrane (eardrum) to vibrate. These vibrations are then transmitted through the ossicles of the middle ear to the oval window, which is the entrance to the cochlea. The movement of the oval window creates waves in the perilymph of the vestibular duct (scala vestibuli), which then travel through the helicotrema to the tympanic duct. The waves in the perilymph of the tympanic duct cause the basilar membrane to move, stimulating the hair cells in the cochlear duct and ultimately leading to the perception of sound.

Clinical significance

Disorders affecting the tympanic duct can lead to hearing loss or tinnitus. Conditions such as Meniere's disease or perilymph fistula can disrupt the normal function of the tympanic duct and the cochlea as a whole.

Related structures

The tympanic duct is part of the cochlea, which also includes the vestibular duct (scala vestibuli) and the cochlear duct (scala media). These three ducts are integral to the process of hearing and are filled with different fluids that facilitate the transmission of sound waves.

References

Pickles, J. O. (2012). An Introduction to the Physiology of Hearing. Brill.
Purves, D., Augustine, G. J., Fitzpatrick, D., et al. (2001). Neuroscience. Sinauer Associates.

Related pages

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-'''Tympanic duct''' (also known as '''scala tympani''') is a perilymph-filled cavity located within the cochlea of the inner ear. It extends from the round window, one of the two openings in the bone that encloses the cochlea, to the helicotrema, where it connects with the [[scala vestibuli]].
+{{Short description|Part of the inner ear involved in hearing}}
+{{Use dmy dates|date=October 2023}}
-==Etymology==
+==Tympanic duct==
-The term "tympanic duct" is derived from the Greek word "tympanon", meaning drum. This is in reference to its location near the tympanic membrane, or eardrum. The term "scala" is Latin for staircase, referring to the spiral structure of the cochlea.
+The '''tympanic duct''', also known as the '''scala tympani''', is one of the three fluid-filled passages in the [[cochlea]] of the [[inner ear]]. It plays a crucial role in the process of [[hearing]] by transmitting sound vibrations from the [[oval window]] to the [[round window]].
-==Structure==
+[[File:Blausen_0329_EarAnatomy_InternalEar.png|thumb|right|Diagram of the internal ear, showing the location of the tympanic duct.]]
-The tympanic duct is one of three fluid-filled spaces within the cochlea. It is separated from the [[scala media]] (the middle chamber) by the [[basilar membrane]], and from the scala vestibuli (the upper chamber) by the helicotrema. The duct is filled with perilymph, a fluid that is high in sodium ions and low in potassium ions.
+==Anatomy==
+The tympanic duct is located in the [[cochlea]], which is a spiral-shaped organ within the [[osseous labyrinth]] of the inner ear. It is situated below the [[cochlear duct]] (scala media) and is separated from it by the [[basilar membrane]]. The tympanic duct is filled with a fluid called [[perilymph]], which is similar in composition to [[cerebrospinal fluid]].
+[[File:Cochlea-crosssection.svg|thumb|right|Cross-section of the cochlea, showing the tympanic duct (scala tympani).]]
 ==Function==
-The primary function of the tympanic duct is to transmit sound vibrations from the cochlea to the brain. When sound waves enter the ear, they cause the eardrum to vibrate. These vibrations are then transmitted to the cochlea via the ossicles, a group of three small bones in the middle ear. Within the cochlea, the vibrations cause the perilymph in the tympanic duct to move, which in turn causes the basilar membrane to move. This movement stimulates the hair cells in the organ of Corti, which send electrical signals to the brain via the auditory nerve.
+The primary function of the tympanic duct is to transmit sound vibrations. When sound waves enter the ear, they cause the [[tympanic membrane]] (eardrum) to vibrate. These vibrations are then transmitted through the [[ossicles]] of the middle ear to the oval window, which is the entrance to the cochlea. The movement of the oval window creates waves in the perilymph of the vestibular duct (scala vestibuli), which then travel through the helicotrema to the tympanic duct. The waves in the perilymph of the tympanic duct cause the basilar membrane to move, stimulating the [[hair cells]] in the cochlear duct and ultimately leading to the perception of sound.
+==Clinical significance==
+Disorders affecting the tympanic duct can lead to hearing loss or [[tinnitus]]. Conditions such as [[Meniere's disease]] or [[perilymph fistula]] can disrupt the normal function of the tympanic duct and the cochlea as a whole.
+==Related structures==
+The tympanic duct is part of the cochlea, which also includes the [[vestibular duct]] (scala vestibuli) and the cochlear duct (scala media). These three ducts are integral to the process of hearing and are filled with different fluids that facilitate the transmission of sound waves.
+[[File:Right_osseous_labyrinth_interior_svg_hariadhi.svg|thumb|right|The osseous labyrinth, showing the cochlea and its ducts.]]
+==See also==
+* [[Cochlea]]
+* [[Inner ear]]
+* [[Hearing]]
+* [[Basilar membrane]]
+==References==
+* Pickles, J. O. (2012). An Introduction to the Physiology of Hearing. Brill.
+* Purves, D., Augustine, G. J., Fitzpatrick, D., et al. (2001). Neuroscience. Sinauer Associates.
-==Related Terms==
+==Related pages==
-* [[Cochlea]]: The spiral-shaped, fluid-filled inner ear structure that is responsible for converting sound vibrations into electrical signals that can be interpreted by the brain.
+* [[Vestibular system]]
-* [[Perilymph]]: The fluid that fills the scala tympani and scala vestibuli in the cochlea.
+* [[Auditory system]]
-* [[Basilar membrane]]: A membrane in the cochlea that separates the scala media from the scala tympani and scala vestibuli.
-* [[Scala vestibuli]]: The upper chamber of the cochlea, which is filled with perilymph and connects to the scala media at the helicotrema.
-* [[Scala media]]: The middle chamber of the cochlea, which is filled with endolymph and contains the organ of Corti.
-* [[Organ of Corti]]: The sensory organ in the cochlea that converts sound vibrations into electrical signals.
-[[Category:Anatomy]]
+[[Category:Auditory system]]
-[[Category:Ear]]
+[[Category:Human anatomy]]
-{{stub}}