![]() The disturbance of motor regulation and the change of muscle fiber properties in the dilating muscles of the upper airway may be an important factor in causing abnormal airway collapse seen in patients with obstructive sleep apnea. However, the muscle fiber changes in specimens from apnea patients showed differentiation between Type I and II fibers, and new types of fibers (Type IIA and IIB) could be identified in these specimens. In normal palatopharyngeus muscles, a normal checkerboard pattern of Type I and II fibers was seen under light microscopy when the fibers were stained for myosin ATPase at pH 9.4. Palatopharyngeus behaves in a similar manner to genioglossus and the other soft palatal muscles, demonstrating phasic respiratory activity and reflex activity in response to upper airway negative pressure. These observations suggest that levator palatini and palatopharyngeus may play a role in the maintenance of upper airway patency. The respiratory activity of palatopharyngeus is greatest when nose-breathing in the supine posture. Palatopharyngeus demonstrate respiratory activity and reflex activation in response to upper airway negative pressure application. Role in respiration and obstructive sleep apnea Therefore, the palatopharyngeal muscle that is elevated and relocated into a transverse incision at the posterior pharyngeal wall (sphincteric pharyngoplasty) is considered more physiological in substituting the Passavant's sphincter because it will have the similar cerebral representation and mimics the same pattern of closure. Orticochea in 1999 believes that movements and functions of the Passavant's sphincter are represented in the brain rather than the muscles. A modification of the latter that has gained so much popularity was introduced by Jackson and Silverton in 1977. The flaps were not sutured to the posterior pharyngeal wall laterally. Therefore, in 1968 Orticochea described the construction of a “dynamic” pharyngeal muscle sphincter in cleft palate patients by suturing the tips of the lateral flaps, containing palatopharyngeus, on to the superior end of a third low inferiorly based posterior pharyngeal flap. ![]() The palatopharyngeus is active in the production of oral sounds as well as nasal speech sounds. The synergistic arrangement of palatopharyngeus and superior constrictor are thought to be important in supporting the primary role of LVP in velopharyngeal closure. The palatopharyngeus assists the swallowing of food, and it elevates the larynx, which assists in the phonation of high pitched sounds. ![]() Role in velopalatal sphincter (speech and swallowing)Īlthough there have been conflicting descriptions of the role of the palatopharyngeus, the general consensus is that it lowers the soft palate and narrows the pharyngeal cavity by its action on the lateral pharyngeal walls during swallowing and speech. This control effect of the muscle (velopharyngeal port opening or closing) was considered with three dimensions radiological reconstruction of pharynx by Serrurier and Badin. The wide distribution of the palatopharyngeus suggests that it acts not only to elevate the pharynx or depress the soft palate, but also as a nasopharyngeal sphincter at the time of opening or closing the pharyngeal isthmus. This fusion leads to a sphincter like behavior as reported by Amelot et al. The Passavant's pad made of the fused fibers of the palatopharyngeus muscle and pterygopharyngeal portion of the superior constrictor as described by Zemlin in 1968. Those complex muscular structures, in particular, the interspersion between muscles from the velum, the nasopharynx, and the tongue. Superiorly, these muscles are the levator and tensor palatini inferiorly they are the palatoglossus and palatopharyngeus. Later, in 1941 Oldfield noted that the muscular elements of the soft palate apart from the uvular muscle consist essentially of four slings these are actually bilateral muscles which affect the sling-like function through their common insertion into the tissues of the soft palate. The first true anatomical descriptions of normal anatomy of the palate and pharynx were published by Von Luschka in Germany in 1868, then in 1935 anatomist James Whillis showed that some fibers of the superior constrictor were inserted into the palatal aponeurosis and constituted lamella he referred to it as the palatopharyngeal sphincter.
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