Sleep

From Canonica AI

Introduction

Sleep is a naturally recurring state of mind and body, characterized by altered consciousness, relatively inhibited sensory activity, reduced muscle activity and inhibition of nearly all voluntary muscles during rapid eye movement (REM) sleep, and reduced interactions with surroundings. It is distinguished from wakefulness by a decreased ability to react to stimuli, but more reactive than a coma or disorders of consciousness, sleep displaying very different and active brain patterns Read more.

Physiology

Sleep is a complex and dynamic process that affects how you function in ways scientists are now beginning to understand. Sleep architecture, or the basic structural organization of normal sleep, has two distinct parts: non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep Read more. Multiple rounds of these stages, known as sleep cycles, occur each night.

A photograph of a person sleeping peacefully in a dark room.
A photograph of a person sleeping peacefully in a dark room.

The process of sleep is regulated by the circadian rhythm, which is influenced by environmental cues like sunlight and temperature. This biological process regulates the timing of periods of sleepiness and wakefulness throughout the day Read more.

Stages of Sleep

Sleep is divided into two types: rapid eye movement (REM) sleep and non-rapid eye movement (NREM) sleep. NREM sleep is further divided into stages 1, 2, and 3.

NREM Sleep

NREM sleep, also known as quiet sleep, consists of three stages. Stage 1 is light sleep where you drift in and out of sleep and can be awakened easily. In stage 2, eye movement stops and brain waves become slower, with occasional bursts of rapid waves called sleep spindles. In stage 3, deep sleep begins and it's harder to awaken. The brain produces slower delta waves and there is no eye movement or muscle activity Read more.

A photograph of a person in deep sleep.
A photograph of a person in deep sleep.

REM Sleep

REM sleep, also known as paradoxical sleep, represents a smaller portion of total sleep time. It is the stage in which most vivid dreams occur, and, as the name suggests, rapid eye movements are a key characteristic of this stage. During REM sleep, several physiological changes also take place. The heart rate and breathing quickens, the blood pressure rises, and the body does not regulate temperature as well Read more.

A photograph of a person experiencing REM sleep.
A photograph of a person experiencing REM sleep.

Sleep Disorders

Sleep disorders, also called somnipathy, are conditions that affect the ability to sleep well on a regular basis. They are often due to stress, health conditions, and excessive noise, among other factors. Sleep disorders are categorized into types that include insomnia, sleep apnea, restless legs syndrome, and narcolepsy Read more.

Sleep and Health

Sleep is essential for maintaining physical health and cognitive functions including memory, learning, and mood regulation. Lack of sleep or poor quality sleep is linked to numerous health problems including heart disease, kidney disease, high blood pressure, diabetes, stroke, obesity, and depression. Sleep also affects growth and stress hormones, the immune system, appetite, breathing, blood pressure, and cardiovascular health Read more.

A photograph of a person sleeping with a sleep monitor.
A photograph of a person sleeping with a sleep monitor.

Sleep in Animals

Sleep in non-human animals refers to a behavioral and physiological state characterized by altered consciousness, reduced responsiveness to external stimuli, and homeostatic regulation. Sleep in different species is complicated by varying definitions of what constitutes 'sleep' Read more.

A photograph of a cat sleeping.
A photograph of a cat sleeping.

See Also

References

1. "Sleep: A Dynamic Activity". National Institute of Neurological Disorders and Stroke. Retrieved 2020-07-15. 2. "Stages of Sleep". American Sleep Association. Retrieved 2020-07-15. 3. "Sleep Disorders". Mayo Clinic. Retrieved 2020-07-15. 4. "How Sleep Deprivation Affects Your Heart". National Sleep Foundation. Retrieved 2020-07-15. 5. "Sleep in Animals". National Sleep Foundation. Retrieved 2020-07-15.