Sexsomnia: A type of parasomnia characterized by sexual and sometimes violent acts towards the bed partner.
Sleep apnea: A sleep disorder that occurs when a person’s breathing is interrupted during sleep.
Sleep architecture: Sleep architecture represents the structure of sleep and is generally composed of a cyclical pattern of the various NREM and REM sleep stages.
Sleep cycle: A sequence of sleep stages that usually begins with a period of NREM sleep followed by REM sleep. Each cycle lasts for approximately 80 to 110 minutes and it is repeated four to six times each night.
Sleep deprivation: Lack of sleep over a period of time resulting in physical or psychiatric symptoms affecting day-to-day functions.
Sleep hygiene: A set of practices, habits, and environmental factors that are important for getting a good night sleep.
Sleep latency: the duration of time required to fall asleep after going to bed.
Sleep onset: the transition from awake to asleep.
Sleep paralysis: A temporary inability to move or speak while falling asleep or waking up, often seen in narcolepsy but also seen after sleep deprivation and other sleep disorders.
Sleep talking (somniloquy): A parasomnia characterized by talking in sleep. It originates from NREM sleep.
Somnambulism (sleep walking): A parasomnia characterized by walking in sleep. Often seen in children, it originates from NREM sleep.
Suprachiasmatic nucleus (SCN): A structure in the human brain that is also known as “internal clock”. It regulates sleep and wake in addition to various other physiological functions.