INFRAHYOID MUSCLES ANATOMYJust below the hyoid bone, a group of thin muscle resembling not much more than mere straps, are grouped. Each has been named for based on their unique origination points along with their insertion points. These muscles are the sternothyroid and the sternohyoid, and the omohyoid and the thyrohyoid muscles.
INFRAHYOID MUSCLES STRUCTUREThe sternohyoid muscle’s origination point runs along the manubrium of the sternum and the insertion point lies on the hyoid bone. Contraction of this muscle leads to depression of the hyoid bone.
The sternothyroid shares the same origination point but its insertion point runs along the thyroid cartilage belonging to the larynx. Contraction of this muscle results in the downward slant of the larynx.
The thyrohyoid is a short muscle. Its origination point runs from the thyroid cartilage and the insertion point runs along the hyoid bone. Contraction of this muscle results in the elevation of the larynx while simultaneously dropping the hyoid bone.
INFRAHYOID MUSCLES DIAGRAM
Image: Infrahyoid Muscles
The omohyoid bone is particularly thin and long. Originating along the superior border of the scapula, its insertion point runs along the hyoid bone. Contraction of this muscle results in depression of the hyoid bone.