A focal weakness or deficiency in this area of the pharyngeal wall is termed a Killian dehiscence and can produce a pulsion-pseudodiverticulum, known as a pharyngeal diverticulum or pouch (Zenker diverticulum). Electromyographic activity of the superior, middle, and inferior pharyngeal constrictor (PC) muscles was examined in 10 normal adult humans during. The area of the pharyngeal wall at the junction between the thyropharyngeus and the cricopharyngeus is a potentially weak area. The middle and superior constrictors are enclosed by the thyropharyngeus fibers that wrap around to the midline raphe Coloring sheets and coloring book pictures.The recurrent laryngeal nerve and inferior laryngeal vessels pass upwards deep to the lower border of the cricopharyngeus.

It is always closed except for momentary relaxation during swallowing. Its closure prevents air from being sucked into the upper esophagus when intrathoracic pressure falls, allowing air to be sucked only into the permanently open trachea. It is physiologically in a tonic state, constricting the distal end of the pharynx (in coordination with the superior pharyngeal constrictor and the middle pharyngeal constrictor muscles). The cricopharyngeus has an important sphincteric function. The muscle is divided into four parts: A pterygopharyngeal, buccopharyngeal, mylopharyngeal and a glossopharyngeal part. Similarly to the superior and inferior pharyngeal constrictor muscles, the middle pharyngeal constrictor is innervated by a branch of the vagus nerve through the pharyngeal plexus. It is one of three pharyngeal constrictors. The muscle is a quadrilateral muscle, thinner and paler than the inferior pharyngeal constrictor muscle and middle pharyngeal constrictor muscle. The middle pharyngeal constrictor is a fan-shaped muscle located in the neck. It acts as a sphincter at the lower end of the pharynx and is always closed except for momentary relaxation during swallowing. It is the highest located muscle of the three pharyngeal constrictors. Its muscle fibers are continuous with the circular muscular coat of the esophagus. Its fibers run continuously from one side of the cricoid arch to the other side around the pharynx without inserting into a midline raphe posteriorly. The cricopharyngeus muscle is rounder and thicker than the other constrictor muscles.

The lower fibers are horizontal and lie edge to edge with those of the cricopharyngeus component. Its fibers curve around posteriorly and insert into the midline raphe. The thyropharyngeus muscle arises from the (a) thyroid cartilage at the oblique line and (b) the tendinous arch that spans the cricothyroid muscle. Other articles where constrictor muscle is discussed: muscle: Comparative anatomy: Constrictors and sphincters diminish the volume of spaces or the area of.

Constrictor muscles