Respiration during feeding on solid food: alterations in breathing during mastication, pharyngeal bolus aggregation, and swallowing.

During feeding, solid food is chewed and propelled to the oropharynx, where the bolus gradually aggregates while the larynx remains open and breathing continues. The aggregated bolus in the valleculae is exposed to respiratory airflow, yet aspiration is rare in healthy individuals. The mechanism for preventing aspiration during bolus aggregation is unclear.

Volitional control of food transport and bolus formation during feeding.

When healthy individuals eat solid food, chewed food is usually transported to the oropharynx where it accumulates before swallowing (stage II transport). We tested the hypothesis that this transport process can be altered by volition. Eight healthy young subjects ate 8 g pieces of cookie with barium while movements were recorded with videofluorography.

Cyclic motion of the soft palate in feeding.

The soft palate moves rhythmically during feeding, but the timing and frequency of this motion are not known. We tested the hypothesis that cyclic soft palate motion is temporally linked to cyclic jaw movement. Nine healthy, asymptomatic human subjects with normal dentition ate solid food coated with barium.

Tongue movements in feeding and speech.

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 concert 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.

Eating and breathing: interactions between respiration and feeding on solid food.

Chewed solid food accumulates in the oropharynx prior to swallowing. The mechanism for preventing aspiration during this interval is unknown, but may be related to respiration. The purpose of this study was to determine how eating, especially bolus formation in the pharynx, affects respiration.