Tragus (ear)
| Tragus | |
|---|---|
 The ear — lateral surface | |
| Details | |
| Identifiers | |
| Latin | Tragus |
| TA98 | A15.3.01.017 |
| TA2 | 111 |
| FMA | 60998 |
| Anatomical terminology | |
The tragus is a small pointed eminence of the external ear, situated in front of the concha, and projecting backward over the meatus. It also is the name of hair growing at the entrance of the ear.[1] Its name comes from the Greek: tragos, goat, and is descriptive of its general covering on its under surface with a tuft of hair, resembling a goat's beard.[2] The nearby antitragus projects forwards and upwards.[3]
Because the tragus faces rearwards, it aids in collecting sounds from behind. These sounds are delayed more than sounds arriving from the front, assisting the brain to sense front vs. rear sound sources.[4]
In a positive fistula test (for the presence of a fistula from cholesteatoma to the labyrinth), pressure on the tragus causes vertigo or eye deviation by inducing movement of perilymph.[5]
Additional images
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Horizontal section through left ear; upper half of section. -
External ear. Right auricle.Lateral view. -
External ear. Right auricle.Lateral view.
Other animals
The tragus is a key feature in many bat species. As a piece of skin in front of the ear canal, it plays an important role in directing sounds into the ear for prey location and navigation via echolocation.[6] Because the tragus tends to be prominent in bats, it is an important feature in identifying bats to species.[7]
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The long tragus of the brown long-eared bat -
The curved tragus of the eastern red bat -
The blunt tragus of the spotted bat
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See also
References
This article incorporates text in the public domain from page 1034 of the 20th edition of Gray's Anatomy (1918)
- ^ "Why do older men have hair growing in their noses and ears?" from The Straight Dope
- ^ Webster. "Tragus : Meanining". Merriam-Webster. Retrieved 13 January 2013.
- ^ "Tragus : Definition". Collins English Dictionary. Retrieved 13 January 2013.
- ^ Muller, Raulf. "A numerical study of the role of tragus in the big brown bat". Research Gate. Retrieved 13 January 2013.
- ^ "Fistula test". Harley Street E-Clinic. Retrieved 13 January 2013.
- ^ Chiu, C., & Moss, C. F. (2007). The role of the external ear in vertical sound localization in the free flying bat, Eptesicus fuscus. The Journal of the Acoustical Society of America, 121(4), 2227-2235.
- ^ "Bats of Wisconsin" (PDF). Wisconsin Department of Natural Resources. Wisconsin Department of Natural Resources. 2013. Retrieved April 11, 2017.
External links
- MedlinePlus Image 1126
- lesson3 at The Anatomy Lesson by Wesley Norman (Georgetown University) (externalear) (#7)
