Final answer:
During both NREM and REM sleep, swallowing and gastrointestinal motility are decreased compared to when awake. Sleep phases, especially REM's muscle atonia, contribute to this decrease, and sleep disorders can further impact these functions and sleep patterns.
Step-by-step explanation:
Swallowing and gastrointestinal motility are decreased from wakefulness during both NREM and REM sleep. During sleep, especially the NREM phase, the body enters a state of reduced activity, which includes a slower rate of gastrointestinal motility. This decrease in gastrointestinal function is part of the body’s overall conservation of energy while we are asleep, with essential bodily functions being prioritized.
Moreover, during REM sleep, the body experiences a state of atonia, or muscle paralysis, which further diminishes physical activities, such as motility and swallowing, known as deglutition. The autonomic nervous system controls the pharyngeal and esophageal phases of deglutition, which become downregulated during sleep. Sleep disorders such as sleep apnea and parasomnias can further affect these processes, leading to disrupted sleep patterns and reduced efficacy of swallowing and motility.