Notes
Infrahyoid Muscles
Because of their actions on the larynx and hyoid bone, the infrahyoid muscles are involved in swallowing and speech.
Deep muscles:
Sternothyroid
- Originates on the manubrium of the sternum and the first costal cartilage and inserts on the oblique line of the thyroid cartilage; it depresses the larynx. It overlies the trachea.
Thyrohyoid
- Originates on the oblique line of the thyroid cartilage
- Inserts on the body of the hyoid
- Depresses the hyoid and elevates the larynx
Superficial muscles:
Sternohyoid
- Originates on the manubrium and the medial end of the clavicle
- Inserts on the body of the hyoid
- Depresses the hyoid
Omohyoid (inferior belly) & Omohyoid (superior belly)
- Originates on the superior border of the scapula and passes through a sling
- Inserts on the body of the hyoid
- Depresses, retracts, and steadies the hyoid