Which intrinsic muscle adducts the vocal cords?

The muscle that adducts the vocal cords is the lateral cricoarytenoid. This intrinsic muscle plays a crucial role in phonation by moving the arytenoid cartilages toward each other, which effectively brings the vocal cords closer together. This action is essential for the closure of the glottis during speech and helps to control airflow through the larynx, allowing for sound production.

While the cricothyroid muscle is involved in tension adjustment of the vocal cords, it primarily works to elongate and tense the cords rather than bringing them together. The thyroarytenoid muscle can also contribute to lowering the pitch of the voice by relaxing the vocal cords, but it does not primarily function in adduction. The posterior cricoarytenoid muscle, on the other hand, is responsible for the abduction of the vocal cords, opening them during breathing. Thus, the lateral cricoarytenoid is the correct choice as the adductor of the vocal cords.