vocalis

The vocalis muscle is the medial portion of the thyroarytenoid muscle, one of the intrinsic muscles of the larynx. It lies within the vocal folds and forms part of the vocal fold body, intimately associated with the vocal ligament and the lamina propria. The thyroarytenoid muscle is commonly described as having a vocalis (inner) and a muscularis (outer) component, with the vocalis occupying the deeper, more tendinous portion adjacent to the vocal ligament.

Functionally, the vocalis tenses the vocal folds by stiffening them from within. Contraction increases the tension of the vocal ligament and vocal folds, contributing to higher pitch and refined control of phonation. It works in concert with the cricothyroid muscle, which also adjusts tension by altering the angle of the thyroid cartilage. Together, these muscles modulate vocal fold tension and length to produce different pitches and vocal qualities.

innervation and clinical considerations The intrinsic laryngeal muscles, including the vocalis, are primarily innervated by the recurrent laryngeal nerve, a branch of the vagus nerve. The cricothyroid muscle, by contrast, is supplied by the external branch of the superior laryngeal nerve. Dysfunction or injury to the recurrent laryngeal nerve can affect vocal fold tension and mobility, leading to hoarseness, reduced range, or breathy voice. Damage or disease affecting the vocalis can contribute to various voice disorders, particularly those involving pitch control and loudness.

Etymology and usage The term vocalis derives from Latin, meaning “of the voice.” In anatomical literature, it distinguishes the inner part of the thyroarytenoid from the outer muscular portion and from the vocal ligament itself.