title: Systematic trends across the night in human sleep cycles.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001927:Brain Diseases / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D006801:Humans; D008875:Middle Aged; D010507:Periodicity; D012016:Reference Values; D012894:Sleep Stages / Q000502:physiology*; D012895:Sleep, REM / Q000502:physiology