Middle pharyngeal constrictor muscle
Encyclopedia
The middle pharyngeal constrictor is a fanshaped muscle, smaller than the Inferior pharyngeal constrictor muscle
.
of the hyoid bone
, from the lesser cornu
, and from the stylohyoid ligament
.
The fibers diverge from their origin: the lower ones descend beneath the Constrictor inferior, the middle fibers pass transversely, and the upper fibers ascend and overlap the Constrictor superior.
It is inserted into the posterior median fibrous raphé
, blending in the middle line with the muscle of the opposite side.
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.
Inferior pharyngeal constrictor muscle
The Inferior pharyngeal constrictor, the thickest of the three constrictors, arises from the sides of the cricoid and thyroid cartilage. Similarly to the superior and middle pharyngeal constrictor muscles, it is innervated by the vagus nerve , specifically, by branches from the pharyngeal plexus...
.
Origin and insertion
It arises from the whole length of the upper border of the greater cornuGreater cornu
The greater cornua of the hyoid bone project backward from the lateral borders of the body; they are flattened from above downward and diminish in size from before backward; each ends in a tubercle to which is fixed the lateral hyothyroid ligament.The upper surface is rough close to its lateral...
of the hyoid bone
Hyoid bone
The hyoid bone is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. At rest, it lies at the level of the base of the mandible in the front and the third cervical vertebra behind.Unlike other bones, the hyoid is only distantly...
, from the lesser cornu
Lesser cornu
The lesser cornua are two small, conical eminences, attached by their bases to the angles of junction between the body and greater cornua of the hyoid bone....
, and from the stylohyoid ligament
Stylohyoid ligament
In connection with the stylohyoideus muscle a ligamentous band, the stylohyoid ligament, may be described.It is a fibrous cord, which is attached to the tip of the styloid process of the temporal bone and the lesser cornu of the hyoid bone....
.
The fibers diverge from their origin: the lower ones descend beneath the Constrictor inferior, the middle fibers pass transversely, and the upper fibers ascend and overlap the Constrictor superior.
It is inserted into the posterior median fibrous raphé
Raphé
Raphé can refer to:* Rafe, a diacritic ֿ a short horizontal overbar placed above certain letters to indicate that they are to be pronounced as fricatives* Raphe, scientific term...
, blending in the middle line with the muscle of the opposite side.
Action
As soon as the bolusBolus (digestion)
In digestion, a bolus is a mass of food that has been chewed at the point of swallowing. Once a bolus reaches the stomach, digestion begins....
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.