Sleep??

[rthmjohn]

I was just curious as to what exactly happens chemically when you go to sleep that makes it so important. I mean, what goes on when you sleep that it takes up a fourth of your lifespan?

[Geog3]

For rest I guess, you sleep to restore your energy and fresh for a new day.

[Sisyphus]

It's still not really all that well understood, but most theories posit that the main function has to do with the brain processing information that it receives during waking hours. Hence, your mind works quicker when you're well rested, and you remember the things which happen right before you go to sleep better than right after. However, this doesn't really explain how some people can adapt to much less sleep than others, etc. So the real answer is, "we don't know yet."

[Glider]

Sisyphus is essentially right. However, although it sould be argued that all brain function is essentially chemical, the importance of sleep seems to be psychological rather than just chemical.

 

It is cognitive function that suffers first with sleep deprivation, reaction times slow, logical thought becomes difficult. This is followed by paranoia, anxiety, depression, hallucinations and eventually death.

[silkworm]

Did you ever hear that we don't really need sleep, we just habitually do it because we had to lay still all night in the early days to keep from being eaten?

 

I know it's bizarre, because everything sleeps, right?

[CanadaAotS]

I heard something like, we physically only need an hour of sleep but mentally need the 6-8...

 

Probably a myth though like the "we only use 10% of our brains" thing

[Connor]

there are severe side effects to sleep deprivation. We definately need sleep.

[Sashatheman]

Did you ever hear that we don't really need sleep' date=' we just habitually do it because we had to lay still all night in the early days to keep from being eaten?

 

I know it's bizarre, because everything sleeps, right?[/quote']

 

but all animals sleep. even the largest of preditors

[rakuenso]

if you've got a brain, you need sleep.

[sorsurus]

okeh..this might be out of topic but i heard that, once, a man tried to change his sleeping habit by staying up all night and sleep during the day. He continued for years and suddenly, he died. Is it a true story? does it related with the sleeping habit that we have? i don't know...

[reng]

I heard something like, we physically only need an hour of sleep but mentally need the 6-8...

 

i don't really know the extent - and this may be contributing to the myth..but there was a sleeping "style"? i've heard where you take 20 minute naps every 4 or 6 hours .. so essentially 80-120 minutes a day. during which time your body will adapt to REM for the entire duration of the nap. along with this though i heard you needed to eat a lot of fruit to have some sort of chemical balance.

[silkworm]

I was thinking about this and I remembered something about either some sort of frog or squirrel not needing sleep, but I couldn't find it.

 

Instead I found this on an animal FAQ:

 

Do fishes sleep?

Some do. For example' date=' the parrotfish sleeps inside a mucous cocoon it makes every night. This blocks its scent from nocturnal predators that might want to eat the parrotfish while it sleeps. Some fishes burrow in the substrate or hide in crevices to rest. Other fishes can't sleep - they need to keep swimming in order to breathe. Sharks and tuna are among the fishes that can't sleep.

[/quote']

 

So, it appears that sharks and tuna don't sleep. I found another reference to certain marine animals not sleeping, but I didn't see any specifics. I found this interesting though:

 

In general, herbivores sleep less then omnivores, who sleep less than carnivores.

 

Maybe something about the cell dealing with what you eat accounts for how much sleep you need.

[Glider]

I was thinking about this and I remembered something about either some sort of frog or squirrel not needing sleep' date=' but I couldn't find it.

 

Instead I found this on an animal FAQ:

 

So, it appears that sharks and tuna don't sleep. I found another reference to certain marine animals not sleeping, but I didn't see any specifics. I found this interesting though:[/quote']

Dolphins (and whales) have the same problem. They can't stop swimming or they will drown, however they still need to sleep. They overcome this problem by sleeping one cerebral hemisphere at a time.

[gcol]

Dolphins (and whales) have the same problem. They can't stop swimming or they will drown' date=' however they still need to sleep. [i']They overcome this problem by sleeping one cerebral hemisphere at a time.[/[/i]QUOTE]

 

Now that was thought provoking. There seem to be many similarities between their brains and ours. I wonder if the problems of light sleepers and sleepwalkers, for example, can be caused by the separate cerebral hemispheres being in different "sleep states"?

[Geog3]

but all animals sleep. even the largest of preditors

 

Thats why eagles for example hunt at night.

[tejaswini]

quite simple when u go to sleep ur body organs specially ur brain will rest as in stop thinking.this does not mean it will stop giving orders , but will stop actions like thinking about matters outside ur body. u get desterssed, relaxed and will wake up fresh to face the mad world once more.

[tejaswini]

I wonder if the problems of light sleepers and sleepwalkers, for example, can be caused by the separate cerebral hemispheres being in different "sleep states"?this was originally by gcol.

hi , i'm very good at the subject but i think sleep walking is seen during the dream stage of sleep when the body usually triggers the release of a chemical that paralyses the body, but people with this disorder aka somnambulism donot have the production of this chemical..hence the behaviour. i don't think it is because of the brain being in different states of sleep. is it possible though?

[tejaswini]

sorry same post.

[insane_alien]

okeh..this might be out of topic but i heard that, once, a man tried to change his sleeping habit by staying up all night and sleep during the day. He continued for years and suddenly, he died. Is it a true story? does it related with the sleeping habit that we have? i don't know...

 

heh my sleep patterns go to this naturally in 1-2 weeks if i don't control when i wake up(alarm clock or otherwise). then it'll cycle round again.

 

I never died though. i don't think his death(if the story is true) had anything to do with his sleep patterns, assuming he got the same amount of sleep just at different times.

[EvoN1020v]

You need to sleep to refresh your brain to stay awake for another 14 to 18 hours per day. Use the image of a battery charger for cellphones, it's kind of the same thing for our brain. (i.e. balance of chemicals). If you don't sleep enough, then you'll get physcially abused from your lack of mental power. You'll get very detorieted.

[rthmjohn]

Thanks for all your input, guys. I really appreciate it, BUT what goes on chemically in your body/brain? I've seen a post that says, "we don't know yet." Is this true?

[Connor]

i'm very good at the subject but i think sleep walking is seen during the dream stage of sleep when the body usually triggers the release of a chemical that paralyses the bodyQUOTE]

 

I thought sleepwalking occured in stage 4 sleep, not REM sleep, I'm not sure though.

 

There are some theories that say sleeping helps one organise their memories and whatnots.

[EvoN1020v]

The amount of sleep a person needs also increases if he or she has been deprived of sleep in previous days. Getting too little sleep creates a "sleep debt," which is much like being overdrawn at a bank. Eventually, your body will demand that the debt be repaid. We don't seem to adapt to getting less sleep than we need, while we may get used to a sleep-depriving schedule, our judgment, reaction time, and other functions are still impaired.

 

Many studies make it clear that sleep deprivation is dangerous. Sleep-deprived people who are tested by using a driving simulator or by performing a hand-eye coordination task perform as badly as or worse than those who are intoxicated. Sleep deprivation also magnifies alcohol's effects on the body, so a fatigued person who drinks will become much more impaired than someone who is well rested. Driver fatigue is responsible for an estimated 100,000 motor vehicle accidents and 1500 deaths each year, according to the National Highway Traffic Safety Administration. Since drowsiness is the brain's last step before falling asleep, driving while drowsy can—and often does—lead to disaster. Caffeine and other stimulants cannot overcome the effects of severe sleep deprivation. The National Sleep Foundation says that if you have trouble keeping your eyes focused, if you can't stop yawning, or if you can't remember driving the last few miles, you are probably too drowsy to drive safely.

 

 

Chemcial properties of sleeping that rthmjohn request:

 

Circadian rhythms are regular changes in mental and physical characteristics that occur in the course of a day (circadian is Latin for "around a day"). Most circadian rhythms are controlled by the body's biological "clock." This clock, called the suprachiasmatic nucleus or SCN, is actually a pair of pinhead-sized brain structures that together contain about 20,000 neurons. The SCN rests in a part of the brain called the hypothalamus, just above the point where the optic nerves cross. Light that reaches photoreceptors in the retina (a tissue at the back of the eye) creates signals that travel along the optic nerve to the SCN.

 

Signals from the SCN travel to several brain regions, including the pineal gland, which responds to light-induced signals by switching off production of the hormone melatonin. The body's level of melatonin normally increases after darkness falls, making people feel drowsy. The SCN also governs functions that are synchronized with the sleep/wake cycle, including body temperature, hormone secretion, urine production, and changes in blood pressure.

 

Source: http://www.medicinenet.com/sleep/page5.htm

[aj47]

i'm very good at the subject but i think sleep walking is seen during the dream stage of sleep when the body usually triggers the release of a chemical that paralyses the bodyQUOTE]

 

I thought sleepwalking occured in stage 4 sleep' date=' not REM sleep, I'm not sure though.

 

There are some theories that say sleeping helps one organise their memories and whatnots.[/quote']

 

Yes sleep walking can only occur during NREM sleep not REM sleep.

 

During REM sleep, all your muscles are paralysed with the exception of your eye muscles and penis.

[Blunt]

I heard something like' date=' we physically only need an hour of sleep but mentally need the 6-8...

 

Probably a myth though like the "we only use 10% of our brains" thing[/quote']

 

 

we need 2 hours physical and then 6-8 mentally as far as i am informed.

 

if you wanna know more you could also check out http://www.howstuffworks.com they have a vey good article on the subject.