Name
Pronunciation
(ster–no-THI-roid)
Origin/Proximal Attachment
Manubrium of the sternum, costal cartilage of 1st rib
Insertion/Distal Attachment
Oblique line of thyroid cartilage
Action/Relevance
Depresses the thyroid cartilage
Innervation
Ansa Cervicalis - C1, 2,3
Notes
On each side of the neck, sternothyroid is one of the muscles of the anterior triangle. It originates from posterior aspect of the manubrium sterni and the posteromedial part of the first costal cartilage.
It passes deep to sternohyoid and runs superomedially. It inserts into the oblique line on the lamina of the thyroid cartilage. It is innervated by branches of the ansa cervicalis (C1-3).
Sternothyroid acts to displace the thyroid cartilage inferiorly. This has the effect of depressing indirectly the hyoid bone. Overall, this has the effect of opening and depressing the larynx.