Sleep architecture

Refers to the time, duration and order (structure and  total sleep time involved) by which EEG sleep stages (stage 1,2,3,4 and REM) or awakenings and arousals are expressed throughout an organism‚was sleep behaviour, including the number of minutes spent in each stage and the order and/or re-occurrences of each stage at any give time of the day or night when sleep occurs

. See EEG stage 1 sleep, EEG stage 2 sleep, EEG stage 3 sleep, Electroencephalogram (EEG), Sleep-waking cycle, REM sleep