The sternohyoid muscle is a bilaterally paired, long, thin, narrow strap muscle of the anterior neck. It is one of the infrahyoid muscles. It is innervated by the ansa cervicalis. It acts to depress the hyoid bone. The sternohyoid muscle is a flat muscle located on both sides of the neck, part of the infrahyoid muscle group. It originates from the medial edge of the clavicle, sternoclavicular ligament, and posterior side of the manubrium, and ascends to attach to the body of the hyoid bone. The sternohyoid muscle, along with other infrahyoid muscles, functions to depress the hyoid bone, which is important for activities such as speaking, chewing, and swallowing. Additionally, this muscle group contributes to the protection of the trachea, esophagus, blood vessels, and thyroid gland. The sternohyoid muscle also plays a minor role in head movements.

Structure

The sternohyoid muscle is one of the paired strap muscles of the infrahyoid muscles. The muscle is directed superomedially from its origin to its insertion. The two muscles are separated by a considerable interval inferiorly, but usually converge by their mid-point and remain proximal until their superior insertion. SternoHyoid

Origin

It arises from the posterior aspect of the medial end (sternal extremity of the

clavicle The clavicle, collarbone, or keybone is a slender, S-shaped long bone approximately long that serves as a strut between the scapula, shoulder blade and the sternum (breastbone). There are two clavicles, one on each side of the body. The clavic ...

, the posterior sternoclavicular ligament, and (the superoposterior portion of) the

manubrium The sternum (: sternums or sterna) or breastbone is a long flat bone located in the central part of the chest. It connects to the ribs via cartilage and forms the front of the rib cage, thus helping to protect the heart, human lung, lungs, and ma ...

sternum The sternum (: sternums or sterna) or breastbone is a long flat bone located in the central part of the chest. It connects to the ribs via cartilage and forms the front of the rib cage, thus helping to protect the heart, lungs, and major bl ...

. It inserts onto the inferior border of the body of

hyoid bone The hyoid-bone (lingual-bone or tongue-bone) () is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid-cartilage. At rest, it lies between the base of the mandible and the third cervical verte ...

Nerve supply

The sternohyoid muscle receives motor innervation from branches of the ansa cervicalis (which are ultimately derived from cervical spinal nerves C1-C3).

Relations

The muscle is situated lateral to the

trachea The trachea (: tracheae or tracheas), also known as the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all animals' lungs. The trachea extends from ...

Variations

The muscle may be absent, doubled, exhibit a clavicular slip (the cleidohyoideus), or interrupted by a tendinous intersection; it sometimes presents a transverse tendinous inscription just distal to its origin.

Actions/movements

The muscle depresses the hyoid bone when the bone is in an elevated position.

Function

The sternohyoid muscle performs a number of functions: * aids in

speech Speech is the use of the human voice as a medium for language. Spoken language combines vowel and consonant sounds to form units of meaning like words, which belong to a language's lexicon. There are many different intentional speech acts, suc ...

(it is primarily involved in modulation with speech

volume Volume is a measure of regions in three-dimensional space. It is often quantified numerically using SI derived units (such as the cubic metre and litre) or by various imperial or US customary units (such as the gallon, quart, cubic inch) ...

rather than intonation). * contributes to movements of the

head A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple ani ...

and

neck The neck is the part of the body in many vertebrates that connects the head to the torso. It supports the weight of the head and protects the nerves that transmit sensory and motor information between the brain and the rest of the body. Addition ...

Additional images

File:Gray116.png, Posterior surface of sternum. File:Gray201.png, Left clavicle. Inferior surface. File:Gray186.png, Hyoid bone. Anterior surface. Enlarged. File:Gray384.png, Section of the neck at about the level of the sixth cervical vertebra. File:Gray390.png, Posterior surface of sternum and costal cartilages, showing Transversus thoracis. File:Gray562.png, The fascia and middle thyroid veins. The veins here designated the inferior thyroid are called by Kocher the thyroidea ima. File:Anterior region of neck (9).JPG, Sternohyoid muscle File:Slide4cc.JPG, Sternohyoid muscle File:Slide3b.JPG, Sternohyoid muscle File:Slide5c.JPG, Sternohyoid muscle - lateral view File:Slide12d.JPG, Sternohyoid muscle - right view File:Slide1g.JPG, Sternohyoid muscle File:Slide2deded.JPG, Muscles, nerves and arteries of neck.Deep dissection. Anterior view.

References

External links

* - "Nerves and Vessels of the Carotid triangle"
PTCentral
{{Authority control Muscles of the head and neck