Through studies conducted on animals, scientists have established that sleep is essential for humans and animals to survive. In this laboratory study, the animal under study was the rat, whose normal lifespan is two years. However, scientists found that rats that have been deprived of the REM sleep stage may die after 5 weeks, while those rats which have been deprived of all sleep stages may die in as little as 3 weeks. An analysis of the sleep deprived rats showed that their bodies display abnormality in temperatures. The paws and tail may develop temperatures which are abnormally low and they may also have sores. The lack of sleep affects the immunity system, and this is one of the reasons as to why the sores develop.
We need sufficient sleep if we want our bodies to function properly. This has a positive influence on how our nervous system functions. People who are sleep deprived and drowsy are not able to concentrate. They are more likely to end up having memory lapses, hampered physical performance and are less likely to be able to carry out calculations accurately. In some extreme cases of sleep deprivation, one may start hallucinating or experiencing mood swings.
According to sleep experts, when we sleep, the neurons get a chance to shut down and carry out some self-repairs. Without adequate sleep, the neurons end up getting polluted and depleted because of the cellular functions taking place in the body. As we sleep, the brain gets a chance to make neuronal connections which may otherwise degenerate due to the lack of activity.
When we are in deep sleep, there is an increased production of growth hormones. There is also reduced protein breakdown and increased cell production. Proteins are responsible for the repair of cells damaged by ultraviolet rays or even stress and therefore deep sleep can also be referred to as beauty sleep. During deep sleep, the part of the brain that deals with social interactions, decision making and emotions experiences reduced activity and this helps in optimizing emotions when we are awake. Researchers established that some nerve signalling patterns that took place during the day in rats were repeated when the rats were in deep sleep. This repeat in patterns improves learning while encoding one's memories.