Hyoid bone
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| Bone: Hyoid bone | |
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| Hyoid bone. Anterior surface. Enlarged. | |
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| Anterolateral view of head and neck. | |
| Latin | os hyoideum |
| Gray's | subject #45 177 |
| Precursor | 2nd and 3rd branchial arch[1] |
| MeSH | Hyoid+Bone |
The hyoid bone (lingual bone) (Latin os hyoideum) is a horseshoe shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. At rest, it lies at the level of the base of the mandible in the front and the third cervical vertebra behind.
It is the only bone in the human skeleton not articulated to any other bone. It is held in place by thyroid ligaments. The hyoid bone provides attachment to the muscles of the floor of the mouth and the tongue above, the larynx below, and the epiglottis and pharynx behind.
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[edit] Segments
The bone consists of a central part, called the body and two pairs of cornua, the greater cornu and the lesser cornu.
- Body of hyoid
- Greater cornu (2)
- Lesser cornu (2)
[edit] Embryology
The second pharyngeal arch gives rise to the lesser cornu of hyoid and the superior part of body of hyoid. Its cartilage of the third pharyngeal arch that forms the greater cornu of hyoid and the lower part of the body of hyoid.
[edit] Ossification
The hyoid is ossified from six centers: two for the body, and one for each cornu. Ossification commences in the greater cornua toward the end of fetal life, in the body shortly afterward, and in the lesser cornua during the first or second year after birth. Till middle age the connection between the body and greater cornu is fibrous.
[edit] Muscle attachments
The following muscles are attached to the hyoid:
- Superior
- Inferior
[edit] Function
Though the hyoid bone is present in many mammals, its descent in living creatures is unique to Homo sapiens, allowing for the production of a wide range of sounds that other animals cannot produce.[2] It allows a wider range of tongue, pharyngeal and laryngeal movements by bracing these structures alongside each other in order to produce variation. The discovery of a modern-looking hyoid bone of a Neanderthal man in the Kebara Cave in Israel led its discoverers to argue that the Neanderthals had a descended larynx, and thus human-like speech capabilities.[3] However, other researchers have claimed that the morphology of the hyoid is not indicative of the larynx's position.[4]
[edit] Fracture and Applied Anatomy
Due to its position, the hyoid bone is not susceptible to easy fracture. In a suspected case of murder, a fractured hyoid strongly indicates throttling or strangulation. However this is not the case in children and adolescents where hyoid bone is still flexible as ossification is yet to be completed.
[edit] Etymology
Its name is derived from the Greek word hyoeides meaning "shaped like the letter upsilon" (υ).
[edit] Additional images
 Head and neck of a human embryo eighteen weeks old, with Meckel's cartilage and hyoid bone exposed. |
 Muscles of the neck. Lateral view. |
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 Sagittal section of the larynx and upper part of the trachea. |
 Coronal section of larynx and upper part of trachea. |
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 The entrance to the larynx, viewed from behind. |
 Sagittal section of nose mouth, pharynx, and larynx. |
 Extrinsic muscles of the tongue. Left side. |
 The thyroid gland and its relations. |
 Front view of neck. |
[edit] See also
[edit] References
- ^ hednk-023 — Embryology at UNC
- ^ http://www.pnas.org/cgi/content/full/100/12/6930 Descent of the larynx in chimpanzee infants
- ^ Arsenburg, B. et al., A reappraisal of the anatomical basis for speech in middle Paleolithic hominids, in: American Journal of Physiological Anthropology 83 (1990), pp. 137-146
- ^ Fitch, Tecumseh W., The evolution of speech: a comparative review, in: Trends in Cognitive Science, Vol. 4, No. 7, July 2000 (http://www3.isrl.uiuc.edu/~junwang4/langev/localcopy/pdf/fitch00speech.pdf)
[edit] External links
- SUNY Labs 25:03-0101 - "Anterior Triangle of the Neck: The Muscular Triangle"
- Roche Lexicon - illustrated navigator, at Elsevier 25420.000-1
- lesson11 at The Anatomy Lesson by Wesley Norman (Georgetown University) (larynxskel1)
- Mnemonic:Muscles attached
This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated.
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