Sleep and body function

But missing out on the recommended 7 to 9 hours of shut-eye nightly does more than make you feel groggy and grumpy. The long term effects of sleep deprivation are real.

Sleep and body function

EEG highlighted by red box. Eye movement highlighted by red line. REM sleep is "paradoxical" because of its similarities to wakefulness. Although the body is paralyzed, the brain acts somewhat awake, with cerebral neurons firing with the same overall intensity as in wakefulness.

Frontal and posterior areas are less coherent in most frequencies, a fact which has been cited in relation to the chaotic experience of dreaming. However, the posterior areas are more coherent with each other; as are the right and left hemispheres of the brain, especially during lucid dreams.

REM sleep is punctuated and immediately preceded by PGO ponto-geniculo-occipital wavesbursts of electrical activity originating in the brain stem. The monoamine neurotransmitters norepinephrineserotonin and histamine are completely unavailable. Injections of acetylcholinesterase inhibitorwhich effectively increases available acetylcholine, have been found to induce paradoxical sleep in humans and other animals already in slow-wave sleep.

Carbacholwhich mimics the effect of acetylcholine on neurons, has a similar influence. In waking humans, the same injections produce paradoxical sleep only if the monoamine neurotransmitters have already been depleted. REM-on neurons are primarily cholinergic i. They are also shorter in duration and more likely to loop back to their starting point.

About seven of such loops take place over one minute of REM sleep. In slow-wave sleep the eyes can drift apart; however, the eyes of the paradoxical sleeper move in tandem. Congenitally blind people, who do not typically have visual imagery in their dreams, still move their eyes in REM sleep.

Heart ratecardiac pressure, cardiac outputarterial pressureand breathing rate quickly become irregular when the body moves into REM sleep. Overall, the brain exerts less control over breathing; electrical stimulation of respiration-linked brain areas does not influence the lungs, as it does during non-REM sleep and in waking.

In females, erection of the clitoris nocturnal clitoral tumescence or NCT causes enlargement, with accompanying vaginal blood flow and transudation i. During a normal night of sleep the penis and clitoris may be erect for a total time of from one hour to as long as three and a half hours during REM.

However, even cats with pontine lesions preventing muscle atonia during REM did not regulate their temperature by shivering. When the body shifts into REM sleep, motor neurons throughout the body undergo a process called hyperpolarization: Muscle inhibition may result from unavailability of monoamine neurotransmitters restraining the abundance of acetylcholine in the brainstem and perhaps from mechanisms used in waking muscle inhibition.

Certain scientific efforts to assess the uniquely bizarre nature of dreams experienced while asleep were forced to conclude that waking thought could be just as bizarre, especially in conditions of sensory deprivation. The prospect that well-known neurological aspects of REM do not themselves cause dreaming suggests the need to re-examine the neurobiology of dreaming per se.

People awakened from REM have performed better on tasks like anagrams and creative problem solving. REM sleep through this process adds creativity by allowing "neocortical structures to reorganise associative hierarchies, in which information from the hippocampus would be reinterpreted in relation to previous semantic representations or nodes.

In the ultradian sleep cycle an organism alternates between deep sleep slow, large, synchronized brain waves and paradoxical sleep faster, desynchronized waves. Sleep happens in the context of the larger circadian rhythmwhich influences sleepiness and physiological factors based on timekeepers within the body.

Sleep and body function

Sleep can be distributed throughout the day or clustered during one part of the rhythm: Many animals and some people tend to wake, or experience a period of very light sleep, for a short time immediately after a bout of REM. The relative amount of REM sleep varies considerably with age.

Central nervous system

The first REM episode occurs about 70 minutes after falling asleep. Cycles of about 90 minutes each follow, with each cycle including a larger proportion of REM sleep. In faster-developing mammals this process occurs in utero. The proportion of REM sleep then decreases significantly in childhood.

Older people tend to sleep less overall but sleep in REM for about the same absolute time, and therefore spend a greater proportion of sleep in REM. Processing of external stimuli is heavily inhibited during phasic REM, and recent evidence suggests that sleepers are more difficult to arouse from phasic REM than in slow-wave sleep.

On recovery nights, an individual will usually move to stage 3 and REM sleep more quickly and experience an REM reboundwhich refers to an increase in the time spent in REM stage over normal levels.

These findings are consistent with the idea that REM sleep is biologically necessary.


There are also positive consequences of REM deprivation. Some symptoms of depression are found to be suppressed by REM deprivation; aggression may increase, and eating behavior may get disrupted. Several reports have indicated that REM deprivation increases aggression and sexual behavior in laboratory test animals.Dec 09,  · For a long time, researchers weren’t quite sure why we sleep.

There are a number of different theories. Some are evolutionary: For instance, sleep keeps us . Continued 8. Losing Sleep Can Make You Gain Weight. When it comes to body weight, it may be that if you snooze, you lose.

Lack of sleep seems to be related to an increase in hunger and appetite. During sleep, your immune system releases proteins called cytokines, some of which help promote sleep. Certain cytokines need to increase when you have an . Rare Genetic Mutation Lets Some People Function with Less Sleep.

Sleep and body function

Ever wished you could get by with less sleep? Some people can--and don't seem to be any worse off for it--thanks, possibly, to one. During sleep, most of the body's systems are in an anabolic state, helping to restore the immune, nervous, skeletal, and muscular systems; these are vital processes that maintain mood, memory, and cognitive function, and play a large role in the function of the endocrine and immune systems.

Sleep is a state that is characterized by changes in brain wave activity, breathing, heart rate, body temperature, and other physiological functions. Depending on the sleep stage, different physiological functions may be more active and variable (for example, during REM sleep), or less active and more stable (for example, during NREM sleep).

Sleep - Wikipedia