Quick Facts
Origin: Posterior surface of manubrium of sternum and costal cartilage of first rib.
Insertion: Oblique line of thyroid cartilage of larynx.
Action: Depresses larynx.
Innervation: Ansa cervicalis (C1-C3), from anterior rami of cervical plexus.
Arterial Supply: Infrahyoid branch of superior thyroid artery.
Origin
The sternothyroid muscle originates from the costal cartilage of the first rib and the posterior surface of the manubrium of the sternum, deep to the attachment of the sternohyoid muscle.
Insertion
The sternothyroid muscle inserts into the oblique line of the thyroid cartilage of the larynx. The oblique line is also the attachment site for the superior constrictor muscle of the pharynx and demarcates the uppermost border of the thyroid gland.
Key Features & Anatomical Relations
The sternothyroid muscle lies deep to the sternohyoid. It is generally wider and lies more medially than the sternohyoid muscle.
Actions
The sternothyroid muscle depresses the larynx after it has been elevated (Standring, 2016).
References
Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series 41st edn.: Elsevier Limited.
