Anatomical considerations of the longitudinal pharyngeal muscles in relation to their function on the internal surface of pharynx.

The aim of this study was to clarify the topography of the longitudinal pharyngeal muscles and to relate the findings to pharyngeal muscular function. Forty-four specimens (22 right and 22 left sides) from embalmed Korean adult cadavers (13 males, 9 females; age range, 46-89 years; mean age, 69.2 years) were used in this study. The palatopharyngeus muscle originated from the palatine aponeurosis and the median part of the soft palate on oral aspect; it ran downward and lateralward, respectively. The palatopharyngeus muscle, which held the levator veli palatini, was divided into two bundles, medial and lateral, according to the positional relationship with the levator veli palatini. The lateral bundle of the palatopharyngeus muscle was divided into two parts: longitudinal and transverse. The pharyngeal longitudinal muscles were classified into the following four types (I-IV) depending on the area of insertion: they were inserted into the palatine tonsil, epiglottis, arytenoid cartilage, piriform recess, thyroid cartilage, and pharyngeal wall. The transverse part of the palatopharyngeus muscle plays a role as a sphincter. Palatopharyngeus and levator veli palatini muscles help each other to function effectively in the soft palate. The present findings suggest that the pharyngeal muscles are involved not only in swallowing but also in respiration and phonation via their attachment to the laryngeal cartilage.