Hyoid bone
Hyoid | |
---|---|
Details | |
Precursor | second and third branchial arch[1] |
Identifiers | |
Latin | os hyoideum |
MeSH | D006928 |
TA98 | A02.1.16.001 |
TA2 | 876 |
FMA | 52749 |
Anatomical terms of bone |
The hyoid bone (lingual bone or tongue-bone) (
Unlike other bones, the hyoid is only distantly articulated to other bones by muscles or ligaments. It is the only bone in the human body that is not connected to any other bones nearby. The hyoid is anchored by muscles from the anterior, posterior and inferior directions, and aids in tongue movement and swallowing. 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.[citation needed]
Its name is derived from Greek hyoeides 'shaped like the letter upsilon (υ)'.[4][5]
Structure
The hyoid bone is classed as an
Body
The body of the hyoid bone is the central part of the hyoid bone.[clarification needed]
- At the front, the body is convex and directed forward and upward.
- It is crossed in its upper half by a well-marked transverse ridge with a slight downward convexity, and in many cases a vertical median ridge divides it into two lateral halves.
- The portion of the vertical ridge above the transverse line is present in a majority of specimens, but the lower portion is evident only in rare cases.[clarification needed]
- The anterior surface gives insertion to the hyoglossusnotches the lateral margin of the geniohyoid attachment.
- Below the transverse ridge the mylohyoid, sternohyoid, and omohyoid are inserted.
- At the back, the smooth, concave, directed backward and downward, and separated from the bursaintervenes between it and the hyothyroid membrane.
- Above, the body is rounded, and gives attachment to the hyothyroid membrane and some genioglossus.
- Below, the body affords insertion medially to the sternohyoid and laterally to the omohyoid and occasionally a portion of the thyrohyoid. It also gives attachment to the Levator glandulae thyreoideae, when this muscle is present.
Horns
The greater and lesser horns (
Greater horns
The greater horns project backward from the outer borders of the body; they are flattened from above downward and taper to their end, which is a bony
Lesser horns
The lesser horns are two small, conical eminences, attached by their bases to the angles of junction between the body and greater horns of the hyoid bone. They are connected to the body of the bone by fibrous tissue, and occasionally to the greater horns by distinct diarthrodial joints, which usually persist throughout life, but occasionally become ankylosed. The lesser horns are situated in the line of the transverse ridge on the body and appear to be continuations of it. The apex of each horn gives attachment to the stylohyoid ligament; the chondroglossus rises from the medial side of the base.[citation needed]
Development
The second pharyngeal arch, also called the hyoid arch, gives rise to the lesser cornu of the hyoid and the upper part of the body of the hyoid. The cartilage of the third pharyngeal arch forms the greater cornu of the hyoid and the lower portion of the body of the hyoid.
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 development, in the hyoid body shortly afterward, and in the lesser cornua during the first or second year after birth. Until middle age the connection between the body and greater cornu is fibrous.
In early life the outer borders of the body are connected to the greater horns by synchondroses; after middle life usually by bony union.
Blood supply
Blood is supplied to the hyoid bone via the
Function
The hyoid bone is present in many
Muscle attachments
A large number of muscles attach to the hyoid:[13]
- Superior
- Middle pharyngeal constrictor muscle
- Hyoglossus muscle
- Genioglossus
- Intrinsic muscles of the tongue
- Suprahyoid muscles
- Inferior
-
Muscles of the neck. Lateral view.
Clinical significance
The hyoid bone is important to a number of physiological functions, including breathing, swallowing and speech. It is also thought to play a key role in keeping the upper airway open during sleep,[14][15] and as such, the development and treatment of obstructive sleep apnea (OSA; characterized by repetitive collapse of the upper airway during sleep). A mechanistic involvement of the hyoid bone in OSA is supported by numerous studies demonstrating that a more inferiorly positioned hyoid bone is strongly associated with the presence and severity of the disorder.[16][17] Movement of the hyoid bone is also thought to be important in modifying upper airway properties, which was recently demonstrated in computer model simulations.[18] A surgical procedure that aims to potentially increase and improve the airway is called hyoid suspension.
Due to its position, the hyoid bone is not easily susceptible to fracture. In a suspected case of murder or physical abuse of an adult, a fractured hyoid strongly indicates throttling or strangulation. In children and adolescents (in whom the hyoid bone is still flexible because ossification is yet to be completed) fracture may not occur even after serious trauma.
Other animals
The hyoid bone is derived from the lower half of the second
In
In
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The hyoid bone of atracheal rings
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Hyoid bones of various birds in the Natural History Museum, Vienna
In veterinary anatomy, the term hyoid apparatus is the collective term used to refer to the bones of the tongue—a pair of stylohyoidea, a pair of thyrohyoidea, and unpaired basihyoideum[21]—and associated, upper-gular connective tissues.[22] In humans, the single hyoid bone is an equivalent of the hyoid apparatus.[23]
See also
References
This article incorporates text in the public domain from page 177 of the 20th edition of Gray's Anatomy (1918)
- ^ hednk-023—Embryo Images at University of North Carolina
- ^ Oxford English Dictionary 2nd edition, 1989.
- ^ Entry "hyoid" Archived 2011-12-29 at the Wayback Machine in Merriam-Webster Online Dictionary Archived 2017-09-22 at the Wayback Machine.
- ^ Dorland illustrated medical dictionary
- ^ American heritage dictionary for English language
- PMID 12775758. Descent of the larynx in chimpanzee infants
- PMID 16730049.
- .
- ^ 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 Sciences, Vol. 4, No. 7, July 2000 ("Archived copy" (PDF). Archived from the original (PDF) on 2007-08-09. Retrieved 2007-09-09.
{{cite web}}
: CS1 maint: archived copy as title (link)) - ^ Granat; et al. (2006). "Hyoid bone and larynx in Homo. Estimated position by biometrics". Biom. Hum. Et Anthropolol. 24 (3–4): 243–255.
- ^ Boë, L.J.; et al. (2006). "Variation and prediction of the hyoid bone position for modern Man and Neanderthal". Biom. Hum. Et Anthropolol. 24 (3–4): 257–271.
- PMID 24262952.
- PMID 24557799.
- PMID 25505028.
- PMID 10673170.
- PMID 25197805.
- PMID 26769952.
- ISBN 0-03-910284-X.
- ^ SeaWorld https://seaworld.org/animals/all-about/cheetah/communication/
- ^ Shoshani J., Marchant G.H. (2001.) Hyoid apparatus: a little-known complex of bones and its "contribution" to proboscidean evolution, The World of Elephants - International Congress, Rome, pp. 668–675.
- ^ Klappenbach, Laura. "Hyoid Apparatus - Definition of Hyoid Apparatus". The New York Times Company. Archived from the original on 2012-01-20. Retrieved 2017-03-20.
- ^ "hyoid apparatus - Definition". mondofacto.com. Archived from the original on 2011-11-08.
External links
- Lesson11 at The Anatomy Lesson by Wesley Norman (Georgetown University) (larynxskel1)