Sleep-induced apnea and disordered breathing refers to intermittent, cyclical cessations or reductions of airflow, with or without obstructions of the upper airway (OSA). In the presence of an anat...

Pathophysiology of Sleep Apnea

The Evolution of Language

Food oral processing - a review.

Saliva has multiple essential functions in relation to the digestive process taking place in the upper parts of the gastrointestinal (GI) tract This paper reviews the role of human saliva and its compositional elements in relation to the GI functions of taste, mastication, bolus formation, enzymatic digestion, and swallowing The indirect function of saliva in the digestive process that includes maintenance of an intact dentition and mucosa is also reviewed Finally, pathophysiological considerations of salivary dysfunction in relation to some GI functions are considered

https://onlinelibrary.wiley.com/doi/epdf/10.1034/j.1601-0825.2002.02851.x

Saliva and gastrointestinal functions of taste, mastication, swallowing and digestion

https://dash.harvard.edu/bitstream/handle/1/3117935/Hauser_EvolutionLanguageFaculty.pdf?sequence=1

The evolution of the language faculty: Clarifications and implications

Food movements during complete feeding sequences on soft and hard foods (8 g of chicken spread, banana, and hard cookie) were investigated in 10 normal subjects; 6 of these subjects also ate 8 g peanuts. Foods were coated with barium sulfate. Lateral projection videofluorographic tapes were analyzed, and jaw and hyoid movements were established after digitization of records for 6 subjects. Sequences were divided into phases, each involving different food management behaviors. After ingestion, the bite was moved to the postcanines by a pull-back tongue movement (Stage I transport) and processed for different times depending on initial consistency. Stage II transport of chewed food through the fauces to the oropharyngeal surface of the tongue occurred intermittently during jaw motion cycles. This movement, squeeze-back, depended on tongue–palate contact. The bolus accumulated on the oropharyngeal surface of the tongue distal to the fauces, below the soft palate, but was cycled upward and forward on the tongue surface, returning through the fauces into the oral cavity. The accumulating bolus spread into the valleculae. The total oropharyngeal accumulation time differed with initial food consistency but could be as long as 8–10 sec for the hard foods. There was no predictable tongue–palate contact at any time in the sequence. A new model for bolus formation and deglutition is proposed.

https://link.springer.com/content/pdf/10.1007%2FPL00009582.pdf

Food Transport and Bolus Formation during Complete Feeding Sequences on Foods of Different Initial Consistency

The position of the tongue relative to the upper and lower jaws is regulated in part by the position of the hyoid bone, which, with the anterior and posterior suprahyoid muscles, controls the angulation and length of the floor of the mouth on which the tongue body 'rides'. The instantaneous shape of the tongue is controlled by the 'extrinsic muscles' acting in con- cert with the 'intrinsic' muscles. Recent anatomical research in non-human mammals has shown that the intrinsic muscles can best be regarded as a 'laminated segmental system' with tightly packed layers of the 'transverse', 'longitudinal', and 'vertical' muscle fibers. Each segment receives separate innervation from branches of the hypoglosssal nerve. These new anatomical find- ings are contributing to the development of functional models of the tongue, many based on increasingly refined finite element modeling techniques. They also begin to explain the observed behavior of the jaw-hyoid-tongue complex, or the hyomandibu- lar 'kinetic chain', in feeding and consecutive speech. Similarly, major efforts, involving many imaging techniques (cinefluo- rography, ultrasound, electro-palatography, NMRI, and others), have examined the spatial and temporal relationships of the tongue surface in sound production. The feeding literature shows localized tongue-surface change as the process progresses. The speech literature shows extensive change in tongue shape between classes of vowels and consonants. Although there is a fundamental dichotomy between the referential framework and the methodological approach to studies of the orofacial com- plex in feeding and speech, it is clear that many of the shapes adopted by the tongue in speaking are seen in feeding. It is sug- gested that the range of shapes used in feeding is the matrix for both behaviors.

/pdf/tongue-movements-in-feeding-and-speech-2gbzovxmd8.pdf

Tongue movements in feeding and speech

Natural bites, food consistency and feeding behaviour in man.

During swallowing, the hyoid bone is described as moving first upward, then forward, then returning to the starting position. This study examined hyoid motion during swallowing of chewed solids and liquids. Barium videofluorography (VFG) was performed on 12 healthy volunteers eating 8-cc portions of various solid foods and drinking liquid. Hyoid position was measured frame-by-frame for 88 swallows relative to the occlusal plane of the upper teeth. The hyoid bone moved both upward and forward during swallowing, but upward displacement was sometimes very small. There was no correlation between the amplitudes of hyoid upward and forward displacements. The amplitude of upward displacement was highly variable, smaller for liquids than for solid foods (p <0.001), and, for solid foods, larger for the first swallow than for the second swallow (p = 0.02). The amplitude of forward displacement did not differ significantly between liquids and solids or between first and second swallows. We conclude that upward displacement of the hyoid bone in swallowing is related primarily to events in the oral cavity, while its forward displacement is related to pharyngeal processes, especially the opening of the upper esophageal sphincter.

Karen M. Hiiemae

Papers

Food Transport and Bolus Formation during Complete Feeding Sequences on Foods of Different Initial Consistency

Tongue movements in feeding and speech

Natural bites, food consistency and feeding behaviour in man.

Hyoid motion during swallowing: factors affecting forward and upward displacement.

Ontogeny of postnatal hyoid and larynx descent in humans.