Sternohyoid muscle
Musculus sternohyoideus
Sternohyoid is a thin infrahyoid strap muscle in the front of the neck, running from the back of the manubrium to the hyoid bone.
At a glance
- English
- Sternohyoid muscle
- Latin (TA2)
- Musculus sternohyoideus
- System
- Muscle
- Region
- Neck
- Side
- Paired, left and right
About the sternohyoid muscle
Sternohyoid is one of the infrahyoid or strap muscles, the flat bands that lie in front of the larynx and trachea below the hyoid bone. It is the most medial and the most superficial of the group in the lower neck, lying just under the investing fascia, with its medial edge close to its partner in the midline above and separating from it lower down.
Its fibres arise from the rear face of the clavicle's inner end, from the ligament behind the sternoclavicular joint and from the top of the manubrium at its back. The muscle runs up and slightly inwards to end by short tendinous fibres on the lower edge of the hyoid body. Along the way it lies beside the trachea and covers sternothyroid and thyrohyoid. A faint transverse tendinous band may cross it just above its origin.
The main job of sternohyoid is to pull the hyoid bone down after it has been raised in swallowing and speech, returning the larynx and tongue base to rest. With the suprahyoid muscles it also steadies the hyoid so that muscles attached to it can act on the jaw and tongue. It plays a part in voice production, mostly by adjusting loudness rather than pitch, and helps in movements of the head and neck.
Its nerve comes from the ansa cervicalis, the loop formed by fibres of C1 to C3. The muscle may be doubled, carry an extra slip from the clavicle (cleidohyoid) or be absent. Surgeons separate the strap muscles in the midline, and sometimes divide them, to reach the thyroid gland, and they are a landmark in tracheostomy.
Attachments, action and supply
- Origin
- Rear face of the clavicle's inner end, the ligament behind the sternoclavicular joint, and the back of the manubrium at its top.
- Insertion
- Lower edge of the hyoid body, near the midline.
- Action
- Depresses the hyoid after swallowing and speech; steadies it with the other hyoid muscles.
- Nerve supply
- Ansa cervicalis (C1 to C3).
- Blood supply
- Superior thyroid artery, with branches of the lingual artery.
Anthromica
See the sternohyoid muscle where it really sits, with every layer of the body around it.
- Every layer, one body. Peel from muscle to bone, nerve, vessel and organ, and turn it any way.
- English and Latin. Every structure named the way your exam names it.
- Quiz until it sticks. Short drills on the structures you keep missing.
Free to start. No card.
