Intrinsic laryngeal muscles can perform which functions?

• A. Adduct or abduct the vocal folds
• B. Tense or relax the vocal folds
• C. None of the above
• D. Both adduct/abduct and tense/relax

Answer: (D)

Intrinsic laryngeal muscles control two aspects of vocal fold function: glottal position and vocal fold tension. They can bring the vocal folds together or pull them apart (adduction and abduction) to regulate whether the glottis is closed for voice or open for breathing. Muscles such as the lateral cricoarytenoid and interarytenoids adduct the folds, while the posterior cricoarytenoid abducts them.

They also adjust tension in the vocal folds, which changes pitch. The cricothyroid muscle lengthens and tenses the folds to raise pitch, whereas the thyroarytenoid (including the vocalis portion) can relax and shorten to lower tension (and adjust pitch as well).

Because these muscles handle both glottal opening/closing and changes in tension, intrinsic laryngeal muscles can perform both adduct/abduct and tense/relax functions.