The suprahyoid muscles are four muscles located above the hyoid bone in the neck. They are the

digastric The digastric muscle (also digastricus) (named ''digastric'' as it has two 'bellies') is a small muscle located under the jaw. The term "digastric muscle" refers to this specific muscle. However, other muscles that have two separate muscle belli ...

stylohyoid The stylohyoid muscle is a slender muscle, lying anterior and superior of the posterior belly of the digastric muscle. It is one of the suprahyoid muscles. It shares this muscle's innervation by the facial nerve, and functions to draw the hyoid ...

geniohyoid The geniohyoid muscle is a narrow muscle situated superior to the medial border of the mylohyoid muscle. It is named for its passage from the chin ("genio-" is a standard prefix for "chin") to the hyoid bone. Structure It arises from the inf ...

, and mylohyoid muscles. They are all

pharyngeal muscles The pharyngeal muscles are a group of muscles that form the pharynx, which is posterior to the oral cavity, determining the shape of its lumen, and affecting its sound properties as the primary resonating cavity. The pharyngeal muscles (involunta ...

, with the exception of the geniohyoid muscle. The

is uniquely named for its two bellies. Its posterior belly rises from the

mastoid process The mastoid part of the temporal bone is the posterior (back) part of the temporal bone, one of the bones of the skull. Its rough surface gives attachment to various muscles (via tendons) and it has openings for blood vessels. From its borders, ...

of the cranium and slopes downward and forward. The anterior belly arises from the digastric fossa on the inner surface of the

mandibular In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movabl ...

body, which slopes downward and backward. The two bellies connect at the intermediate tendon. The intermediate tendon passes through a connective tissue loop attached to the hyoid bone. The

mylohyoid muscle The mylohyoid muscle or diaphragma oris is a paired muscle of the neck. It runs from the mandible to the hyoid bone, forming the floor of the oral cavity of the mouth. It is named after its two attachments near the molar teeth. It forms the fl ...

s are thin, flat muscles that form a sling inferior to the tongue supporting the floor of the mouth. The

s are short, narrow muscles that contact each other in the midline. The

s are long, thin muscles that are nearly parallel with the posterior belly of the digastric muscle.

Function

These four muscles have different actions, but in general assist in elevating the hyoid bone and widening the

esophagus The esophagus ( American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to ...

during swallowing. When the two bellies of the

contract, they pull upward on the hyoid bone; but if the hyoid is fixed from below, the

assists in extreme opening of the mouth such as yawning or taking a large bite of an apple. The mylohyoid elevates the hyoid bone, tenses the floor of the mouth. The

Geniohyoid The geniohyoid muscle is a narrow muscle situated superior to the medial border of the mylohyoid muscle. It is named for its passage from the chin ("genio-" is a standard prefix for "chin") to the hyoid bone. Structure It arises from the inf ...

pulls the hyoid bone anterosuperiorly, shortening the floor of the mouth and widening the pharynx during swallowing. The

Stylohyoid The stylohyoid muscle is a slender muscle, lying anterior and superior of the posterior belly of the digastric muscle. It is one of the suprahyoid muscles. It shares this muscle's innervation by the facial nerve, and functions to draw the hyoid ...

elevates and retracts the hyoid bone, elongating the floor of the mouth during swallowing.

References

{{DEFAULTSORT:Suprahyoid Muscles Muscles of the head and neck

Function

See also

References