Locate the recurrent (inferior) laryngeal nerve and the inferior laryngeal artery. The inferior laryngeal artery is a branch of the inferior thyroid artery. The recurrent laryngeal nerve lies between the trachea and the esophagus. The inferior laryngeal nerve supplies all the muscles of the larynx except the cricothyroid muscle. It also conveys sensation from the mucous membrane below the vocal folds.
As the inferior laryngeal nerve courses near the larynx, it is passed on its posterior aspect by the inferior thyroid artery. During thyroidectomy, care must be taken when ligating the inferior thyroid artery to avoid damaging the inferior laryngeal nerve. Injury to the inferior laryngeal nerve may result in paralysis of the laryngeal muscles. If the laryngeal muscles are paralyzed only on one side, there is hoarseness of the voice and inability to tightly close the rima glottidis.
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