Recurrent Laryngeal Nerve - Path

Path

It is referred to as "recurrent" because the branches of the nerve innervate the laryngeal muscles in the neck through a rather circuitous route: it descends into the thorax before rising up between the trachea and esophagus to reach the neck.

The left laryngeal nerve, which is longer, branches from the vagus nerve to loop under the arch of the aorta, posterior to the ligamentum arteriosum before ascending. On the other hand, the right branch loops around the right subclavian artery. As the recurrent nerve hooks around the subclavian artery or aorta, it gives off several cardiac filaments to the deep part of the cardiac plexus. As it ascends in the neck it gives off branches, more numerous on the left than on the right side, to the mucous membrane and muscular coat of the esophagus; branches to the mucous membrane and muscular fibers of the trachea; and some pharyngeal filaments to the superior pharyngeal constrictor muscle.

The nerve splits into anterior and posterior rami before supplying muscles in the voice box – it supplies all laryngeal muscles except for the cricothyroid, which is innervated by the external branch of the superior laryngeal nerve.

The recurrent laryngeal nerve enters the pharynx, along with the inferior laryngeal artery and inferior laryngeal vein, below the inferior constrictor muscle to innervate the Intrinsic Muscles of the larynx responsible for controlling the movements of the vocal folds.