Sleep

Article

Sleep is a recurring biological state characterised by reduced interaction with the environment, altered consciousness, distinctive brain activity, and changes in muscle tone, breathing, circulation, hormone release, and metabolism.

Human sleep is organised into non-rapid-eye-movement sleep and rapid-eye-movement sleep. These stages recur in ultradian cycles during the night, while the timing of sleep is regulated by interaction between circadian rhythms and a homeostatic pressure that increases during wakefulness.

Sleep contributes to memory, learning, emotional regulation, immune function, metabolic regulation, tissue repair, and brain maintenance. The exact functions of sleep remain an active area of research and may differ among sleep stages and species.

Sleep duration and architecture vary with age, health, environment, behaviour, and individual biology. Sleep deprivation, circadian disruption, breathing disorders, insomnia, movement disorders, and neurological or psychiatric conditions can impair sleep quality and daytime function.

Source details and credits

• Source / publisher: Wikipedia
• URL type: WWW
• Credits: Wikipedia
• URL: https://en.wikipedia.org/wiki/Sleep