Why do we sleep?

Why do we spend quarter of a day sleeping?

                                     


Sleep is a naturally recurring state characterized by reduced or absent consciousness, relatively suspended sensory activity, and inactivity of nearly all voluntary muscles. It is distinguished from quiet wakefulness by a decreased ability to react to stimuli, and is more easily reversible than being in hibernation or a coma. Sleep is a heightened anabolic state, accentuating the growth and rejuvenation of the immune, nervous, skeletal and muscular systems. It is observed in all mammals, all birds, and many reptiles, amphibians, and fish.

We feel sleepy when we are tired after work.At night we feel sleepy.Why does one feel sleepy? It is the rest acquired through sleep that makes us energetic.Sleep is essential to remove fatigue and to maintain health .                                                                          
               Numerous  studies are being done on sleep.Then brain controls all the functions of the body.It has been concluded that the part called cerebellum in the brain controls sleep.When we work for the whole day,the quantity of calcium increases in our blood.Sleep is essential to reduce the quantity of calcium.It is the brain which gives the instruction to sleep.

                  When calcium was directly injected into the brain of animals,they soon fell down sleeping but when calcium was injected into the blood they didn't sleep.Thus,it has been concluded that it is not only the quantity of calcium but something else is also the cause of sleep.Research is progressing.Let us wait for the progress.