Why do we need to sleep?

Question

Its something we spend half our lives doing, why do we need to?

Answer 1

Most sighted animals tend to have a hard time at night because, without light, they can't do certain important things as well as they could in bright daylight - like protect themselves from injury or hunt/gather successfully.

Humans, like other animals, frequently undergo mutations in our genes from one generation to another. Each new generation may give an opportunity to those mutations that bring an advantage to the individual animal, to increase in numbers and become widespread in the gene pool of the population of that animal.

Even if it is only a small advantage, if it only allows individuals with that gene to give birth on avarage to (say) 2.5 children per generation instead of 2.4 children, successive generations of the advantaged animal will dominate more and more in numbers until - after a few generations - very few of the disadvantaged individuals will be found in the population.

We feel the need for sleep because, for those animals in whom sight is a dominant sense, the avoidance of injury and other harm caused by lack of light at night, will give an advantage to those individuals whose mental make-up happens to mutate to a form that favours a day / night - waking / sleeping pattern. One way for this to happen is if the animal's internal chemistry alters in time of darkness to make the animal want to rest instead of remaining active.

On the other hand, nocturnal animals can exploit a niche left by animals who mainly sleep at night, by being active at night themselves to (e.g.) avoid predators. In nocturnal animals, specialised night-vision, highly developed hearing, smell and/or other senses can help give these animals a greater advantage over their competitors at night than they would enjoy during the day.

Answer 2

One theory is that the brain must have this down time in order to make sense of all the information it has come across during the day. It is kind of like filing away all the info. The body does need rest. During the hours of 11pm and approx 3am the body repairs itself such as repairing muscle.
If you type this into a search engine "Theories of why we sleep" it'll come up with some answers

Answer 3

This is an hard question.
The only necessary phase of sleep is the so-called "slow wave" phase, i.e. if you get deprived from it, you will not survive. During the slow wave phase the sleep is very deep and you don't experience any dreams.
On the contrary, the rem phase is not necessary, there are people who lack it without any recognizable health effects.
The main hypotheses on why do we need to sleep focus around the consolidation of memories and the synaptic homeostatis.

Answer 4

The purpose of sleep is still a mystery but so far research has shown that sleep helps to store all the material you were exposed to during the day into the part of your brain responsible for short and long term memory. It is also thought that we use sleep to strengthen our immune system. How it is strengthen is still a mystery but there is a strong correlation between a weak immune system and sleep deprivation.
Hope this helps :)

Answer 5

We need sleep to renew the energy in our body. It also helps you unwind.

Sleeping occurs in several cycles which includes:- enhanced repairing of tissue and muscles you have used during the day, repair of the immune system, memory consolidation, and brain restoration. Although all this happens as you sleep there are times you can wake up still tired as whilst you are dreaming your mind can be as active, if not more active as when you're awake.

Answer 6

We spend nearly 25 yrs just sleeping.
Actually our body never sleeps. The digestion goes on, breathing and cell division and chemical activties. It is a situation like stand by.
Then who sleeps? Our soul sleeps

Answer 7

Sleep gives the brain a chance to rest, but also helps in the healing process of the body. It's a rejuvenation process.

Answer 8

yea ive stayed up for almost 5 days straight....not good. oh and ideally its only about a third of our lives we spend sleeping. i hope youre not sleeping 12 hours a day, that would be a waste

Answer 9

Have you ever stayed up for a couple of days? your brain starts to play tricks and you can start to hallucinate. so you need to sleep for the sake of your mind!!

Answer 10

Ssshhhhhhhhhhhhhh! If someone hears you asking that we might never be allowed to sleep again and I'd really hate that! I do soooooooooo love my bed :)