Name
Pronunciation
(ster-no-HI-oid)
Origin/Proximal Attachment
Manubrium of the sternum
Insertion/Distal Attachment
Body of hyoid, inferior border
Action/Relevance
Depresses the hyoid
Innervation
Ansa Cervicalis - C1, 2,3
Notes
Sternohyoid describes each of a pair of strap muscles within the neck. Its action is to depress the hyoid bone and larynx as might occur, for example, in the latter phases of swallowing.
On each side, it originates from the posterosuperior surface of the manubrium sterni and adjoining medial part of the clavicle. It inserts into the inferolateral surface of the hyoid bone. The muscles of both sides are closest at their insertion but diverge inferolaterally to their origins.
The relations of sternohyoid include:
* laterally:
* and superiorly: omohyoid
* and inferiorly: sternocleidomastoid
* medially:
* and superiorly: laryngeal prominence of thyroid cartilage
* and inferiorly: pretracheal fascia overlying trachea
* deep:
* and superiorly: thyroid lobes
* and inferiorly: carotid sheath
Sternohyoid is supplied by the ventral rami of C1 to C3 via the ansa cervicalis nerve. Ipsilaterally and inferiorly, the nerve enters into the muscle before ascending and supplying it in a segmental manner.