Definitions for "Sleep cycle"
Keywords:  rem, nrem, cycle, night, minute
Synonymous with NREMS-REMS cycle.
Formed by the two phases of sleep, non-REM and REM sleep. One complete sleep cycle lasts approximately 90 minutes. People go through two to five of these sleep cycles in a typical night's sleep.
A repeating pattern of sleep stages. Normal individuals experienced four to five sleep cycles during the course of a normal 8-hour sleep period.