Anatomy

Origin

Thyropharyngeal part: On the thyroid cartilage it arises from the oblique line on the side of the lamina, from the surface behind this nearly as far as the posterior border and from the inferior cornu. Cricopharyngeal part: From the cricoid cartilage it arises in the interval between the Cricothyreoideus in front, and the articular facet for the inferior cornu of the thyroid cartilage behind.

Insertion

From these origins the fibers spread backward and medialward to be inserted with the muscle of the opposite side into the fibrous pharyngeal raphe in the posterior median line of the pharynx.

Nerve

It is innervated by the vagus nerve (CN X), by branches from the pharyngeal plexus and by neuronal branches from the recurrent laryngeal nerve.

Actions

As soon as the bolus of food is received in the pharynx, the elevator muscles relax, the pharynx descends, and the constrictors contract upon the bolus, and convey it downward into the esophagus. During deglutition, they contract and cause peristaltic movement in the pharynx.