Muscle, Stylopharyngeus (M. Stylopharyngeus, Pna, Bna; M. Stylopharyngicus, Jna)

The stylopharyngeal sphincter muscle (pharyngeal sphincter) is a striated trunk muscle that narrows the entrance to the pharynx and, when relaxed, opens it for the passage of bolus food and air. The action is carried out through the narrowing of the subpharyngeal part of the esophagus and the connective muscle (sphenoid), which is attached to the tongue. Located on the back of the pharynx between the back wall of the soft palate and the stylohyoid muscles. It is attached in front to the hyoid bone, and below - to the uvula of the pharynx. Its processes enter the spaces between the stylepiglottic muscles, and a branch of the maxillary nerve passes there. Its main function is closure. In addition, this muscle prevents the backflow of food from the pharynx into the oral cavity during vomiting. Closing the pharynx increases the pressure and elasticity of the chyme, which causes salivation. Normally, the muscle is completely turned off. But if a person wants to suppress the gag reflex or strains excessively during bowel movements, its activation may occur, and then increased pressure on the caudal region may occur