A member of the infrahyoid group of muscles, the thyrohyoid muscle elevates the thyroid gland while depressing the hyoid bone. These actions play a role in swallowing and speech. The thyroid gland is located in the center of the neck, just above the collarbone. The hyoid lies in the neck, just below the lower jawbone, or mandible.
A small muscle, the thyrohyoid looks like a vertical extension of the sternothyroideus muscle within the neck. It originates in the thyroid cartilage (the Adam’s apple), and it inserts into the greater cornu of the hyoid bone, which is the hyoid’s back-most area.
The first cervical nerve supplies the thyrohyoid with nerves. It extends out from the atlas bone, which is the topmost vertebra of the spinal column. For a brief stretch, the first cervical nerve also joins the hypoglossal nerve, which controls the movement of the tongue.
The thyrohyoid muscle is not the only muscle attached to the hyoid. The middle pharyngeal constrictor, the digastric, the omohyoid, and other muscles are located in close proximity. The hyoid bone itself is a curved structure in the throat made up of a central body and areas where muscles and ligaments attach, called the greater and lesser cornu. The hyoid helps protect the thyroid gland and other anatomical components located in the upper throat.