Thyroarytenoid muscle causes: (A) Adduction of vocal cord, (B) Tenses vocal cord, (C) Relaxes vocal cord, (D) Closes inlet of larynx
Answer is C. Thyroarytenoid muscle is relaxor of vocal cord. Vocalis muscle which is medial fibre of thyroarytenoid, causes tension in anterior ⅓ and relaxation in posterior ⅔ of vocal cord.