A 65 year old man presented with vocal cord palsy. He is a pan chewer since childhood. On examination, his abducting function of vocal cord is impaired. The nerve affected is:: (A) External laryngeal nerve, (B) Recurrent laryngeal nerve, (C) Mandibular nerve, (D) Vagus nerve
Answer is B. The sole abductor of the vocal cords is the posterior cricoarytenoid muscle which is innervated by recurrent laryngeal nerve. Innervation of the Vocal Cord: Muscle Nerve Adductors (lateral cricoarytenoid, thyroarytenoid, interarytenoids) Recurrent laryngeal (adductor branch) Posterior cricoarytenoid Recurrent laryngeal (abductor branch) Cricothyroid External laryngeal