The sternohyoid muscle is a thin, narrow muscle attaching the hyoid bone to the sternum, one of the paired strap muscles of the infrahyoid muscles serving to depress the hyoid bone. It is innervated by the ansa cervicalis.
The omohyoid muscle is a muscle that depresses the hyoid. It is located at the front of the neck and consists of two bellies separated by an intermediate tendon. Its superior belly serves as the most lateral member of the infrahyoid muscles, located lateral to both the sternothyroid and thyrohyoid muscles. Its name derives from the Greek "omos" meaning shoulder, giving one of its attachments, and "hyoid", giving the other attachment - the hyoid bone.
The Sternothyreoideus (or Sternothyroid muscle) is shorter and wider than the Sternohyoideus, beneath which it is situated.
The thyrohyoid muscle
is a small skeletal muscle
on the neck which depresses the hyoid and elevates the larynx.