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The transition muscle between the palatopharyngeus (PP) and the superior constrictor of the pharynx (SCP) encircles the pharyngeal isthmus from behind and is designated as the palatopharyngeal sphincter (PPS). The PPS is inferred to play important roles for velopharyngeal closure, but its existence remains controversial and its roles have been regarded as being played by the SCP. The present study aimed to clarify the anatomical status and functional implications of the PPS. Macroscopic and microscopic examinations were performed on 39 and 4 cadavers, respectively. In the former, the bilateral PPSs and their adjacent structures were exposed from outside and/or inside. In the latter, the velums embedded in paraffin were cut into frontal or sagittal sections and alternately processed with HE and Azan stains. The PPS originated from the nasal aspect of the lateral half of the palatine aponeurosis and the inferior margin of the medial pterygoid plate and was distinguishable from the PP descending in and along the palatopharyngeal arch and the cranialmost portion of the SCP in its origin. It passed dorsally on the lateral side of the levator veli palatini and traversed around the salpingopharyngeal fold running longitudinally. It then entered below the SCP and ran toward the pharyngeal raphe with SCP muscle fibers intermingled. The PPS is a muscle distinct from the SCP. Its contraction produces Passavant’s ridge and conceivably enhances the efficiency of velopharyngeal closure by pressing the salpingopharyngeal fold and the musculus uvulae ridge against the velum.

Much is known about lunge feeding in balaenopterid whales, but many key aspects of structure, function, and behavior have not yet been explained in detail, especially with regard to concentrating, positioning, and swallowing large aggregations of prey. We describe a novel system of three integrated structural components, all of which are involved in sequential feeding activities (intraoral transport, filtration, and swallowing of prey) that follow lunge-feeding engulfment of prey-laden water in rorquals: (1) a hammock-like muscular sling comprising extrinsic lingual musculature along the midline of the ventral pouch; (2) the flattened scoop-like arrangement of caudal-most baleen plates converging in the oropharynx adjacent to the esophageal opening; and (3) a flow-diverting flange at the posterior dorsum of the lip, by a flow channel at the angle of the mouth. Subsequent to contraction of the ventral pouch and concomitant expulsion of the mouthful of ingested water, these three structures together, we contend, aid in (1) channeling prey posteriorly toward the esophageal opening; (2) concentrating prey as excess water is squeezed from (what is presumed to be) the slurry-like mixture of nektonic and/or planktonic prey and water; and (3) guiding prey into the isthmus of the fauces while simultaneously (4) facilitating expulsion of water. These related functions occur along with, and are in part achieved by, elevation and retraction of the tongue and oral floor. Given their presumed functional role, these systems are best described as a suite of integrated structural adaptations. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 300:2070-2086, 2017. © 2017 Wiley Periodicals, Inc.

Effective ‘valving’ in the upper aerodigestive tract (UAT) is essential to temporarily separate the digestive and respiratory pathways. Marine mammals are largely dedicated to feeding underwater, and in many cases swallowing prey whole. In seals, little work has been done to explore the anatomy and function of the upper aerodigestive tract in the context of valving mechanisms that function to separate food and air pathways. Here we use videofluoroscopy, gross dissection, histology and CT renderings to explore the anatomy of the larynx and soft palate in the harbour seal (Phoca vitulina), and generate models for how valving mechanisms in the head and neck may function during breathing, phonating, diving and swallowing. Harbour seals have an elevated larynx and the epiglottis may rise above the level of the soft palate, particularly in pups when sucking. In addition, the corniculate and arytenoid cartilages with associated muscles form most of the lateral margins of the laryngeal inlet and vestibule, and move independently to facilitate airway closure. The corniculate cartilages flex over the laryngeal inlet beneath the epiglottis to completely close the laryngeal vestibule and inlet. The vocal folds are thick and muscular and the medial margin of the folds contains a small vocal ligament. The soft palate has well-defined levator veli palatini muscles that likely function to elevate the palate and close the pharyngeal isthmus during feeding. Our results support the conclusion that harbour seals have evolved UAT valving mechanisms as adaptations to a marine environment that are not seen in terrestrial carnivores.

Background For soft palate defects of more than two-thirds, we previously described the bent anterolateral thigh (ALT) method in which the pharyngeal isthmus was reconstructed as a tunnel structure. In this study, we compared the new “tunnel structure” reconstruction in our bent ALT flap method and the traditional “port structure” reconstruction. Methods From April 2010 to March 2015, 25 patients in Saitama Cancer Center (Saitama, Japan) underwent oropharyngeal tumor resection including soft palate resection. In patients who had soft palate resection of less than two-thirds, the Gehanno method was performed in 10 patients (the data were shown as a comparison). In patients who had soft palate resection of more than two-thirds, the pharyngeal isthmus was reconstructed as a tunnel structure using the bent ALT flap method in eight patients and as a port structure in seven patients. The functional outcomes were assessed by interviewing patients about their symptoms and measuring the standard articulation test. Results Postoperative function was favorably maintained at equal levels in the tunnel structure reconstruction group and the Gehanno method group at approximately 12 months postoperation. However, in most patients in the port structure reconstruction group, the pharyngeal isthmus became larger after 12 months postoperation and the articulation test was significantly worse than the Gehanno group and the tunnel group. Conclusion The bent ALT flap method had superior results to the conventional method. Thus the pharyngeal isthmus should be reconstructed as a tunnel structure for patients with soft palate defects of more than two-thirds.