Why Do You Think We Sleep? Essay Example

Introduction

The term sleep has been defined in many ways, this notwithstanding there are more accepted versions of the definitions. According to Harvey (1937) sleep is the natural state which is recurrent that is characterized by reduced muscle activity, absent consciousness, and suspended sensory activity. On the same note Zisapel (2007) defines sleep as high anabolic rate so as to give way to rejuvenation and growth of the nervous, skeletal, immune and muscular systems of the body. It occurs virtually in all living things. Generally speaking sleep is that period in our daily lives that we do nothing but rest.

For a long time, this has been a subject of great interest among scientists, scholars and psychologists alike. They have spent considerable amounts of resources trying to unearth this question as to why we sleep. Why do some animals sleep less than two hours a day while others sleep for more than half of the day? Do plants also sleep? Despite their endeavors to come up with a conclusive answer to these queries, up to date there has not been a single universally accepted answer as to why we sleep. Nonetheless they have come up with answers to some aspects of sleep and some theories as to why human beings and animals need sleep. They have been discussed below.

Sleep theories

The inactivity theory

This is one of the earliest theories that were advanced by evolution scientists in their attempt to explain why animals sleep. The theory holds that animals need to sleep during the night such that they avoid the danger of being attacked by predators or even involved in accidents due to darkness. These scientists claim that this was part of natural selection which ensured that those animals that slept had higher chances of survival whereas those that did not sleep were eliminated. Thus in the end we only had animals that must sleep!

Of course just like many other theories, the inactivity or adaptive theory had its own critics. One of such critics argue that if the sole reason for animals to sleep was to stay safe, wouldn’t it had been better if they remained inactive but conscious? It is much safer to stay alert so as to react to danger whenever it arises than to sleep unconsciously. A valid reasoning indeed or isn’t it?

The energy conservation theory

This theory holds that we sleep in order to conserve energy. This has been greatly supported by scientific experimentation. It has been demonstrated beyond reasonable doubt that organism’s energy demands falls by more than 10% (in humans) and even more than that in other animals when they are asleep than when they are active. This, the theorists claim, is very important for living organisms to survive especially when there is scarcity of energy resources. Whereas this seems to be objective reasoning, it has not been spared critics. One such criticism argues that if animals sleep majorly to conserve energy (which is deemed to be scarce according to evolution theorists) why then animals with plenty of resources also sleep?

The restorative theory

This is one of the most recent theories that seek to explain why animals sleep. It argues that human beings and animals a like need to sleep in order to restore and rejuvenate worn out tissues during the period they have been active or awake. This theory has a lot of scientific backing perhaps explaining why it has gained a lot of popularity. One such evidence is that experiments have shown that animals which have been derived of sleep totally die in a matter of weeks. Additionally some body processes have been demonstrated to take place mostly (if not only) during sleep. These include tissue repair, muscle growth, growth hormone release and protein synthesis.

The brain plasticity theory

This is yet another modern theory attempting to explain why we sleep. The proponents of this theory argue that sleep is so much correlated to the changes in organization and structure of the brain. This phenomenon is the one that has been termed as brain plasticity. It is still under research and conclusive answers have not been given. One of the supporting findings in this theory is that babies sleep for about 14 hours a day so that their brains could develop. Similarly whenever an individual seems to have a mental disorder like after an accident, he goes on a comma such that his brain could reorganize and restructure to normal. There has been also growing evidence of special link between brain plasticity and sleep even in normal adults. This has been demonstrated in experiments involving sleep and sleep deprived individuals. Individuals who get good sleep undoubtedly work, reason and perform variety of tasks very well than their sleep deprived counterparts.

Conclusion

Whereas all this theories have some scientific and common sense backing in their attempt to explain why animals sleep, none gives a conclusive answer on its own. Thus we can confidently say that we sleep due to all of this reasons that have been advanced by these four theories. Modern theories are only attempting to give empirical evidence to long known facts. In conclusion remember that irrespective of whether one day we will have a self sufficient answer as to why we sleep or not, one thing remains clear: sleep is a very vital part of our lives. Therefore we should spare ourselves some good time and have a good sleep if we are to be productive besides staying healthy.