Sleep Vocab Flashcards

Circadian rhythms are the physical, mental, and behavioral changes an organism experiences over a 24-hour cycle. Light and dark have the biggest influence on circadian rhythms, but food intake, stress, physical activity, social environment, and temperature also affect them.

a series of thoughts, images, and sensations occurring in a person's mind during sleep

a machine used for electroencephalography.

Hypersomnia is a condition in which you feel extreme daytime sleepiness despite getting sleep that should be adequate (or more than adequate). If you have hypersomnia, you fall asleep several times during the day.

Insomnia is a common sleep disorder. With insomnia, you may have trouble falling asleep, staying asleep, or getting good-quality sleep. This happens even if you have the time and the right environment to sleep well. Insomnia can get in the way of your daily activities and may make you feel sleepy during the day.

Melatonin is a hormone that your brain produces in response to darkness. It helps with the timing of your circadian rhythms (24-hour internal clock) and with sleep. Being exposed to light at night can block melatonin production.

A nap is a short period of sleep that usually occurs during the day. For many adults, naps can help to maintain alertness or overcome daytime fatigue. Nap needs and the benefits of napping can vary among individuals.

What is narcolepsy? Narcolepsy is a chronic neurological disorder that affects the brain's ability to control sleep-wake cycles. People with narcolepsy may feel rested after waking, but then feel very sleepy throughout much of the day.

What are night terrors? Night terrors are a sleep disorder in which a person quickly awakens from sleep in a terrified state. The cause is unknown but night terrors are often triggered by fever, lack of sleep or periods of emotional tension, stress or conflict.

Overview. A nightmare is a disturbing dream associated with negative feelings, such as anxiety or fear that awakens you. Nightmares are common in children but can happen at any age. Occasional nightmares usually are nothing to worry about.

Parasomnias occur in a state that lies between sleep and wakefulness. A person with parasomnias may seem to be alert, walking or talking or eating or doing other such activities but without awareness because the brain is only partially awake.

A condition characterized by a nearly irresistible urge to move the legs, typically in the evenings.

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.

Sleep apnea is a potentially serious sleep disorder in which breathing repeatedly stops and starts. If you snore loudly and feel tired even after a full night's sleep, you might have sleep apnea.

Summary. Read the full fact sheet. Sleep deprivation occurs when an individual fails to get the amount of sleep that they need. Sleep deprivation can occur due to various lifestyle, work, and environmental factors. Sleep disorders and other chronic medical conditions can also cause sleep deprivation.

Sleep paralysis is a feeling of being conscious but unable to move. It occurs when a person passes between stages of wakefulness and sleep. During these transitions, you may be unable to move or speak for a few seconds up to a few minutes. Some people may also feel pressure or a sense of choking.

Polysomnography, a type of sleep study, is a multi-parameter study of sleep and a diagnostic tool in sleep medicine. The test result is called a polysomnogram, also abbreviated PSG.

Overview. Snoring is the hoarse or harsh sound that occurs when air flows past relaxed tissues in your throat, causing the tissues to vibrate as you breathe. Nearly everyone snores now and then, but for some people, it can be a chronic problem. Sometimes it may also indicate a serious health condition.

Stage 1, also called N1, is essentially when a person first falls asleep. This stage normally lasts just one to seven minutes. During N1 sleep, the body has not fully relaxed, though the body and brain activities start to slow with periods of brief movements.

During stage 2, or N2, the body enters a more subdued state including a drop in temperature, relaxed muscles, and slowed breathing and heart rate. At the same time, brain waves show a new pattern and eye movement stops.

Stage 3. Stage 3 sleep is also known as N3 or deep sleep, and it is harder to wake someone up if they are in this phase. Muscle tone, pulse, and breathing rate decrease in N3 sleep as the body relaxes even further. The brain activity during this period has an identifiable pattern of what are known as delta waves.

In the deepest level of sleep, stage IV sleep, the predominant EEG activity consists of low frequency (1–4 Hz), high-amplitude fluctuations called delta waves, the characteristic slow waves for which this phase of sleep is named. The entire sequence from drowsiness to deep stage IV sleep usually takes about an hour.

The act of getting up and walking around while asleep.

Wakefulness is a daily recurring brain state and state of consciousness in which an individual is conscious and engages in coherent cognitive and behavioral responses to the external world. Being awake is the opposite of being asleep, in which most external inputs to the brain are excluded from neural processing.