Light micrograph of a section through cartilage from the larynx (voice box). Cell nuclei and the collagen fibres that form the cartilage are stained black. This is an area of the larynx called the arytenoid. There are a pair arytenoids, attached to the vocal folds, or cords, and the pharyngeal muscles. When the muscles contract they pull their ligaments tight and stretch the vocal folds out into the air passageways. If air is directed against the vocal folds, they vibrate to produce sound. Magnification: x100 when printed at 15cm wide.