innervates superior pharyngeal constrictor muscle. quizlet

Medially, the buccinator is covered by the cheek's submucosa and mucosa. The parotid duct (Stenson's duct) pierces the buccinator muscle after crossing the masseter muscle. Laterally, the buccinator is related to the mandibular ramus, masseter and medial pterygoid muscles, buccal fat pad, and buccopharyngeal fascia. The maxillary bundle fibers blend with the orbicularis oris muscle fibers at the mandibular lip. The mandibular bundle fibers run superiorly to the maxillary lip. The longitudinal bundle fibers travel toward the oral commissures to insert into the upper and lower lips. The fibers of all 3 bundles run anteriorly and descend through the modiolus, thus forming the musculature of the cheek. The buccinator fibers blend with orbicularis oris muscle fibers. The maxillary bundle arises from the buccal portion of the maxilla's alveolar process. The mandibular bundle originates from the buccal portion of the mandible's alveolar process. The longitudinal bundle emerges from the pterygomandibular raphe. The raphe connects the buccinator's posterior fibers to the superior constrictor muscle, the most superior pharyngeal constrictor (see Image. The buccinator muscle fibers originate from 3 areas, giving rise to 3 muscular bundles. Two of the muscular bundles have a bony origin. The veins draining the buccinator empty into the pterygoid plexus and internal maxillary vein. The posterosuperior alveolar artery is a branch of the maxillary artery that enters the buccinator muscle posterosuperiorly and supplies the area. The facial artery then runs anterosuperiorly to give off anterior buccal branches, which supply the anterior aspect of the muscle. Inferior buccal branches of the facial artery supply the inferior portion of the buccinator. The posterior buccal branch, the largest facial artery segment, supplies the posterior aspect of the muscle. The facial artery supplies the buccinator's posterior, inferior, and anterior parts via its numerous branches. This artery runs anteroinferiorly, either superficial or deep, to the lateral pterygoid muscle to reach the buccinator's posterior aspect. The buccal artery, a maxillary artery branch, supplies the buccinator's posterior part. These vessels form an extensive anastomosis on the muscle's lateral surface and within its fibers. The main blood supply to the buccinator comes from the buccal, facial, and posterosuperior alveolar arteries. Studies also reveal that the buccinator helps regulate parotid secretion, having small fibers inserted in the distal portion of the parotid duct. The buccinator is activated during mandibular movements like protrusion and retrusion, aiding in completing these actions. This wave is subsequently transmitted to the pharynx. The buccinator and orbicularis oris generate a peristaltic wave-like contraction during the oral phase. The buccinator plays a role in the oral and pharyngeal phases of swallowing. Research also shows that the muscle contributes to parafunctional movements, which include bruxism, finger-sucking, and thumbsucking. The buccinator helps retain and stabilize complete dentures. These actions maintain cheek tension, preventing buccal mucosal injury. The muscle contracts gradually while closing the mouth and relaxes when the mouth opens. The buccinator's contraction pulls the corner of the mouth laterally. This thickening enables the cheek to push food boluses toward the tongue. Some authors propose that the muscle thickens the cheek mucosa, acting as a muscular hydrostat. The buccinator compresses the cheek inward against the molars.

The buccinator muscle is sometimes referred to as an accessory mastication muscle as it coordinates with the orbicularis oris and superior constrictor muscle during swallowing, mastication, blowing, and sucking. The buccinator lies deep to the facial skin, anterior border of the masseter, and more superficial muscles. The muscle then inserts on the mouth's angle (modiolus) and the orbicularis oris. The buccinator, the main cheek muscle, originates from the mandible, the maxilla's alveolar process, the mandible's alveolar part, and the pterygomandibular raphe.

Innervates superior pharyngeal constrictor muscle. quizlet