Although deglutition can be caused consciously, in most instances it is caused subconsciously.
Frequency of deglutition is one per minute, which means that during day and night more than 1000 swallowing movements may occur. Decrease of swallowing activity occurs during sleep.
Beyond food and saliva transportation, deglutition may be protective in nature. In collaboration with respiratory movements, breath is stopped during deglutition, so the entrance of food into trachea is avoided.
In case of food entrance into trachea, apart from other protective reflexes, activation of deglutition occurs that contributes to the cleaning of airways.
Mechanisms of deglutition are complex processes requiring the collaboration of extended parts of the brainstem, cranial nerves, sensory receptors and muscles. Masticatory process is programmed through neural circuits in brainstem’s “masticatory center”. If masticatory center is activated for a first time, masticatory process becomes then automatic.
Total Pages: 71-75 (5)
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