Resources >> Articles >> Vocal Anatomy and Physiology >> The Structures of the Larynx
The Structures of the Larynx
The larynx is suspended from the hyoid bone. The hyoid bone is horseshoe-shaped, lying flat with the open end at the back, and is the only bone in the body that is not directly connected to another bone. It is possible to locate the hyoid bone from outside by feeling gently just below the base of the tongue.
The thyroid cartilage is suspended below the hyoid bone. It is the largest structure in the larynx and it gives the familiar prominence on men’s necks known as the Adams Apple. The word thyroid means shield, and like a shield, the thyroid cartilage is open at the back.
Directly below the thyroid cartilage is the cricoid cartilage. The cricoid cartilage is the lowest cartilage in the larynx, sitting at the top of the trachea or windpipe. The word cricoid means like a ring, and it looks like a signet ring lying on its side, with the narrow part at the front and the widest part at the back. The cricoid and thyroid cartilages are attached to each other on each side by a tiny joint. This means the cartilages can change their position in relation to each other.
At the back of the larynx is a pair of small three-sided pyramids called the arytenoid cartilages. These sit on the top back edge of cricoid cartilage, pointing forwards. The foremost point of the base of each arytenoid cartilage is called the vocal process, and it is to this point that the rear of each vocal fold is attached. The vocal folds then run forward to insert at a point at the inside centre of the thyroid cartilage.
On the top of the larynx is the epiglottis, also a cartilage, though more bendy and pliable than the other cartilages. The epiglottis forms a lid on the larynx. The epiglottis attaches to the inner surface of the thyroid cartilage just above the point where the vocal folds are fixed. Muscles attaching to the epiglottis enable it to be pulled down to seal and protect the more delicate internal structures of the larynx during swallowing.
There are two other tiny sets of cartilages found in the larynx. These are the cuneiform cartilages and corniculate cartilages. The cuneiform cartilages are embedded in tissue that joins the epiglottis to the arytenoids cartilages. They can usually be seen clearly as bulges when the larynx is viewed by an endoscope. The corniculate cartilages sit on the upper-most point of the arytenoids cartilages.
The hyoid bone, thyroid and cricoid cartilages can be usually located by gently feeling the front of the neck. This sometimes takes a bit of practise, especially on a female larynx, which is generally smaller and flatter than the male larynx. The other cartilages are positioned deeper in the structure and so cannot be located through touch.
© 2005-2009 Voicesource Limited
