Respiration During Sleep
Regulation of respiration differs significantly between sleep and wakefulness. With sleep onset, there occur important changes in the various processes that regulate respiratory control. Behavioral influences on respiration terminate with cessation of input from the waking state. Positional changes typically associated with sleep also result in significant alterations in respiratory mechanics. Finally, sleep is a dynamic physiologic state with further varying effects on respiration seen in specific sleep stages, particularly in rapid eye movement (REM) compared with non–rapid eye movement (NREM) sleep.
Source : Respiratory Disorders and Sleep, An Issue of Sleep Medicine Clinics (The Clinics: Internal Medicine)