Sleep, Sleep disorders, Biological rhythms Biomedical Technology II (Honors)
Sleep Natural part of life REQUIRED FUNCTION Spend about 1/3 of life asleep REQUIRED FUNCTION
Sleep Research unable to identify function of sleep, though its necessity has been repeatedly proven Rats deprived of sleep will die within 2-3 weeks, similar timeframe to starvation Sleep is a dynamic process What does this mean?
Biology of sleep Characteristic physiological changes in the organs of the body How can sleep be measured? Electroencephalogram (EEG) Electrooculogram (EOG) Electromyogram (EMG)
Biology of sleep The use of these measures has helped us identify two basic stages of sleep: Non-rapid eye movement (NREM) and Rapid eye movement (REM)
NREM 4 stages based on amplitude and frequency of brain wave (EEG) activity In general, EEG pattern of NREM is slower and more regular than when awake As sleep gets deeper, the brain waves get slower and have greater amplitude
REM EEG during REM sleep shows fast and desynchronized activity Similar to EEG from awakeness Characterized by bursts of rapid eye movement Eye movement is not constant, but instead consists of a darting back and forth/up and down Movement is synchronous between eyes as when awake Dreaming is believed to occur during this stage, however the why still remains unanswered
Sleep Cyclic process; people experience repeated cycles of NREM and REM sleep, beginning with REM Cycle lasts about 90-110 min; repeated 4-6 times per night As the night progresses, deep NREM decreases and REM increases