The palatopharyngeus muscle is a long muscle that extends throughout the entire length of the soft palate and terminates within the pharynx. Therefore, it is classified not only as a muscle of the soft palate, but it is also a longitudinal muscle (levator) of the pharynx.
Within the soft palate, it forms the palatopharyngeal arch together with the mucosa that covers it. The originating muscle fibers are composed of two fasciculi (muscular bands) that are separated by the levator veli palatini muscle:
- The anterior fasciculus is thicker than the posterior. It originates from the posterior border of the hard palate and the superior surface of the palatine aponeurosis.
- The posterior fasciculus arises from the palatine aponeurosis. In the midline, it blends with the fibers of the posterior fasciculus of the contralateral muscle.
Both fasciculi meet at the posterolateral border of the soft palate, where the fibers of the salpingopharyngeus muscle also join them. The palatopharyngeus descends laterally behind the palatine tonsil along the lateral wall of the oropharynx, forming the palatopharyngeal arch.
Then the muscle continues to descend posteromedially and reaches the stylopharyngeus muscle. Along with the stylopharyngeus, the palatopharyngeus attaches to the posterior border of the thyroid cartilage of the larynx. Some fibers of the palatopharyngeus also terminate within the lateral wall of the pharynx, while others cross the midline posteriorly and blend with the fibers of the contralateral palatopharyngeus muscle.
Insertion: posterior and superior borders of the thyroid cartilage, lateral wall of the pharynx, fibers of the contralateral palatopharyngeus muscle (muscle of the opposite side).
Action: elevates the pharynx and pulls it superiorly, anteriorly and medially. The palatopharyngeus shortens the pharynx during swallowing, effectively closing off the nasopharynx from the oropharynx. It draws the larynx and esophagus towards the root of the tongue. Also, it tenses the soft palate and brings the palatopharyngeal arches closer together.