The Sternothyroideus (or sternothyroid muscle) is a muscle in the neck. It is shorter and wider than the sternohyoideus, beneath which it is situated.Superficial dissection of the right side of the neck, showing the carotid and subclavian arteries.The fascia and middle thyroid veins.Hypoglossal nerve, cervical plexus, and their branches.Side view of the larynx, showing muscular attachments.Sternothyroid muscle The Sternothyroideus (or sternothyroid muscle) is a muscle in the neck. It is shorter and wider than the sternohyoideus, beneath which it is situated. It arises from the posterior surface of the manubrium sterni, below the origin of the sternohyoideus, and from the edge of the cartilage of the first rib, and sometimes that of the second rib, it is inserted into the oblique line on the lamina of the thyroid cartilage.