Coordination of Respiration, Swallowing, and Chewing in Healthy Young Adults

Abstract

Examining the coordination of respiration and swallowing is important for elucidating the mechanisms underlying these functions and assessing how respiration is linked to swallowing impairment in dysphagic patients. In this study, we assessed the coordination of respiration and swallowing to clarify how voluntary swallowing is coordinated with respiration and how mastication modulates the coordination of respiration and swallowing in healthy humans. Twenty-one healthy volunteers participated in three experiments. The participants were asked to swallow 3 ml of water with or without a cue, to drink 100 ml of water using a cup without breathing between swallows, and to eat a 4-g portion of corned beef. The major coordination pattern of respiration and swallowing was expiration–swallow–expiration (EE type) while swallowing 3 ml of water either with or without a cue, swallowing 100 ml of water, and chewing. Although cueing did not affect swallowing movements, the expiratory time was lengthened with the cue. During 100-ml water swallowing, the respiratory cycle time and expiratory time immediately before swallowing were significantly shorter compared with during and after swallowing, whereas the inspiratory time did not differ throughout the recording period. During chewing, the respiratory cycle time was decreased in a time-dependent manner, probably because of metabolic demand. The coordination of the two functions is maintained not only in voluntary swallowing but also in involuntary swallowing during chewing. Understanding the mechanisms underlying respiration and swallowing is important for evaluating how coordination affects physiological swallowing in dysphagic patients.

Coordination between respiration and swallowing in patients with dysphagia after cervical spinal cord injury: an observational case-control study

“…The present study found that the IE ratio during swallowing in healthy individuals was 1:1.64, which is consistent with previous ndings [15] , and the IE ratio in patients who had CSCI without dysphagia was similar to that in healthy individuals. In contrast, the inspiratory time is longer than the expiratory time during feeding in patients with dysphagia, which may be because the maximum inspiratory pressure of the patients with dysphagia is lower than the patients without dysphagia.…”

The voice and swallowing profile of adults with laryngotracheal stenosis before and after reconstructive surgery: A prospective, descriptive observational study

“…In the normal population the 100 mL WST test has been used to help identify respiratory coordination patterns-expiration-swallow-expiration is most common. 11 In this study, the results of the 100 mL WST highlight a disparity between normative values for swallow volume and capacity. LTS impacts breathing therefore it is hypothesized that there is disruption to the coordinated respiratory-swallow patterns required for rapid, sequential drinking.…”

“…In the normal population the 100 mL WST test has been used to help identify respiratory coordination patterns‐expiration–swallow‐expiration is most common 11 . In this study, the results of the 100 mL WST highlight a disparity between normative values for swallow volume and capacity.…”

Neuropeptide Modulation Enables Biphasic Inter-network Coordination via a Dual-Network Neuron

“…In addition to phasic coordination, there may be correlated changes in the overall activity levels of related networks such as increased respiratory activity to match more intense forms of locomotion, or increased swallowing frequency to match increased chewing rates (Hao et al, 2021; Hérent et al, 2023). In the crustacean STNS, when the pyloric and gastric mill networks are both active, their activity level is coordinated such that faster pyloric rhythms occur with faster gastric mill rhythms (Bartos et al, 1999; Powell et al, 2021; Saideman et al, 2007).…”