Hyoid bone.html



Bone: Hyoid bone
Hyoid bone. Anterior surface. Enlarged.
Anterolateral view of head and neck.
Latin	os hyoideum
Gray's	subject #45 177
Precursor	2nd and 3rd branchial arch1
MeSH	Hyoid+Bone

The hyoid bone (lingual bone) (Latin os hyoideum) is a bone in the neck, and is the only bone in the human skeleton not articulated to any other bone. It is connected to the thyroid cartilage; supported by the muscles of the neck and in turn supports the root of the tongue.

The hyoid bone is shaped like a horseshoe, and is suspended from the tips of the styloid processes of the temporal bones by the stylohyoid ligaments.

Segments

It consists of five segments:

• body of hyoid
• greater cornu (2)
• lesser cornu (2)

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.

Muscle attachments

The following muscles are attached to the hyoid:²

• superior
  • Middle pharyngeal constrictor muscle
  • Hyoglossus muscle
  • Digastric muscle
  • Stylohyoid muscle
  • Geniohyoid muscle
  • Mylohyoid muscle
  • Genioglossus
• inferior
  • Thyrohyoid muscle
  • Omohyoid muscle
  • Sternohyoid muscle

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.³ 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.⁴ However, other researchers have claimed that the morphology of the hyoid is not indicative of the larynx's position.⁵

Fracture

Due to its position, the hyoid bone is not usually easy to fracture in most situations. In cases of suspicious death, a fractured hyoid is a strong sign of strangulation. However this is not the case in adolescents due to the fact that it is still flexible.

Etymology

Its name is derived from the Greek word hyoeides meaning "shaped like the letter upsilon" (υ).

Additional images

Larynx	Head and neck of a human embryo eighteen weeks old, with Meckel’s cartilage and hyoid bar exposed.	Muscles of the pharynx and cheek.	Muscles of the neck. Lateral view.
The internal carotid and vertebral arteries. Right side.	The ligaments of the larynx. Antero-lateral view.	Sagittal section of the larynx and upper part of the trachea.	Coronal section of larynx and upper part of trachea.
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.

See also

• Bone terminology
• Terms for anatomical location
• Adam's apple

References

External links

• SUNY Labs 25:03-0101 - "Anterior Triangle of the Neck: The Muscular Triangle"
• Roche Lexicon - illustrated navigator, at Elsevier 25420.000-1
• Norman/Georgetown lesson11 (larynxskel1)

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. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.