Superior pharyngeal constrictor muscle
The superior pharyngeal constrictor muscle is a quadrilateral muscle of the pharynx. It is the uppermost and thinnest of the three pharyngeal constrictors.
The muscle is divided into four parts according to its four distincts origins: a pterygopharyngeal, buccopharyngeal, mylopharyngeal, and a glossopharyngeal part. The muscle inserts onto the pharyngeal raphe, and pharyngeal spine. It is innervated by pharyngeal branch of the vagus nerve via the pharyngeal plexus. It acts to convey a bolus down towards the esophagus, facilitating swallowing.
Anatomy
The superior constrictor muscle is a quadrilateral, sheet-like muscle. It is thinner than the middle and inferior constrictor muscles.Origin
The sites of origin of the muscles collectively are the pterygoid hamulus anteriorly, the pterygomandibular raphe, the posterior extremity of the mylohyoid line of mandible, and the side of the tongue.Four parts of the muscle are distinguished according to the origin:Pterygopharyngeal part - originating from the lower third of the posterior margin of the medial pterygoid plate and its hamulusBuccopharyngeal part - originating from the pterygomandibular rapheMylopharyngeal part - originating from the alveolar process of the mandible above the posterior end of the mylohyoid lineGlossopharyngeal part - a few fibers originating from the side of the tongue
Insertion
The muscle's fibres extend posterior-ward from its origin to form the midline pharyngeal raphe which then attaches onto the pharyngeal tubercle.Innervation
The superior pharyngeal constrictor muscle receives motor innervation from the pharyngeal plexus of vagus nerve.Vasculature
Arterial supply is provided primarily by the pharyngeal branch of the ascending [pharyngeal artery], and the tonsilar branch of the facial artery.Relations
The interval between the upper border of the muscle and the base of the skull is closed by the pharyngeal aponeurosis, and is known as the sinus of Morgagni.There is an interval between superior pharyngeal constrictor and middle pharyngeal constrictor, this space contains glossopharyngeal nerve, lingual nerve and the stylopharyngeus muscle.
The superior fibers arch beneath the levator veli palatini muscle and the Eustachian tube.