front 1 Circadian rhythm | back 1 the physical, mental, and behavioral changes an organism experiences over a 24-hour cycle. |
front 2 dreams | back 2 a series of thoughts, images, and sensations occurring in a person's mind during sleep |
front 3 Electroencephalograph (EEG) | back 3 a recording of brain activity. |
front 4 Hypersomnia | back 4 a condition in which you feel extreme daytime sleepiness despite getting sleep that should be adequate (or more than adequate) |
front 5 Insomnia | back 5 having trouble falling asleep, staying asleep, or getting good quality sleep. |
front 6 Melatonin | back 6 a hormone that your brain produces in response to darkness |
front 7 Napping | back 7 sleeping for a short time during the day |
front 8 Narcolepsy | back 8 a chronic neurological disorder that affects the brain's ability to control sleep-wake cycles |
front 9 Night Terrors | back 9 a sleep disorder in which a person quickly awakens from sleep in a terrified state |
front 10 Nightmares | back 10 a disturbing dream associated with negative feelings, such as anxiety or fear that awakens you |
front 11 Parasomnia | back 11 Parasomnias occur in a state that lies between sleep and wakefulness |
front 12 Restless Legs Syndrome | back 12 a condition that causes a very strong urge to move the legs |
front 13 Sleep | back 13 a condition of body and mind that typically recurs for several hours every night, in which the eyes are closed, the postural muscles relaxed, the activity of the brain altered, and consciousness of the surroundings practically suspended |
front 14 Sleep apnea | back 14 a potentially serious sleep disorder in which breathing repeatedly stops and starts |
front 15 Sleep deprivation | back 15 occurs when an individual fails to get the amount of sleep that they need |
front 16 Sleep paralysis | back 16 a temporary inability to move or speak that occurs directly after falling asleep or waking up |
front 17 Sleep study | back 17 a test used to diagnose sleep disorders |
front 18 Snoring | back 18 the action or fact of making a snorting or grunting sound while asleep |
front 19 Stage 1 (Non-REM) sleep | back 19 heartbeat, eye movements, brain waves, and breathing activity begin to taper down |
front 20 Stage 2 (Non-REM) sleep | back 20 You are in light sleep. Your heart rate slows and your body temperature drops. |
front 21 Stage 3 (Non-REM) sleep | back 21 deep sleep, and it is harder to wake someone up if they are in this phase. |
front 22 Stage 4 (REM Sleep) | back 22 your voluntary muscles become immobilized. Your brain also uses this time to cement information into memory, making it an important stage for learning |
front 23 Somnambulism | back 23 sleep walking |
front 24 Wakefulness | back 24 a condition of being alert, rather than sleepy. |