Which muscle is responsible for increasing pitch by elongating the vocal cords?

The muscle that is responsible for increasing pitch by elongating the vocal cords is the cricothyroid muscle. This muscle plays a crucial role in fine-tuning the tension of the vocal folds. When the cricothyroid muscle contracts, it tilts the thyroid cartilage forward and downward, which stretches or elongates the vocal cords. This elongation tightens the vocal folds, resulting in a higher pitch during phonation.

Understanding how pitch is regulated involves recognizing the roles of various intrinsic laryngeal muscles. The cricothyroid muscle specifically adjusts the length and tension of the vocal cords, while other muscles, such as the thyroarytenoid, interact with the cords but primarily assist in thickening or shortening them, which is not the main action for increasing pitch. Therefore, the cricothyroid is key in controlling the pitch of the voice by affecting the vocal fold dynamics through elongation.