Head and neck muscles (chewing, facial, and throat muscles)

Sternothyroid Muscle

Musculus sternothyroideus

Origin

Posterior surface of the manubrium sterni and the first costal cartilage

Insertion

Oblique line of the thyroid cartilage

Function

Pulls the larynx downward, e.g. after swallowing or during low-pitch phonation

Innervation

Ansa cervicalis (C2-C3), via the superior and inferior roots

Movement & chain

Part of the infrahyoid ('strap') muscle chain; together with the omohyoid and sternohyoid muscles it pulls the laryngeal skeleton downward after its upward displacement during swallowing, and stabilizes the hyoid-laryngeal complex during phonation.

Palpation

Palpable deep in the lower anterior neck between sternum and thyroid lamina.

Clinical

Landmark in thyroid surgery: the infrahyoid ('strap') muscles, including the sternothyroid, are divided in the midline or retracted to access the thyroid gland.

Segmental innervation

C2-C3 (ansa cervicalis).

In clinical practice

Depresses larynx following high-pitch phonation and swallowing; mobilized during thyroid and parathyroid surgery.

Region in the model

Head and neck muscles (chewing, facial, and throat muscles)