Sleep is an unavoidable requirement of life. Every living being needs to sleep. Sleep is a bodily need that takes up abut one-third of one’s life span. After a day’s work, both brain and body get tired. Sleep is thus necessary to restore energy ad freshness to the tired organs and tissues of the body. It enables the body to repair worn out tissues and cells.
Do you know why we feel an urge to sleep and what happens to our body during sleep? According to scientific facts, there is a very complex area in the brain called sleep centre.
Calcium ions present in the blood, control this centre. When the sleep centre receives an optimum quantity of calcium, we feel sleepy. It has been observed from experiments on animals that they start sleeping when calcium is injected directly into the sleep centre.
But if calcium is injected into the blood stream, this does not happen. During sleep, the sleep centre does two things. Firstly, it blocks the brain so that we have no will power or consciousness left and secondly, it blocks all nerves leading to the brain so that our internal organs and limbs fall asleep.
Do you think that all our body activities stop when we sleep? No, they don’t.
In sleep, our body continues making many types of movements. A man on a average changes his sides 20 to 40 times during sleep in one night.
Blood circulation continues during sleep. Heartbeat slows down a little bit but does not stop the digestive system works normally. Liver and kidneys perform their functions. The effect of sound, light, heat, smell, etc., in sleep is the same on every sleeping person. During sleep, the body temperature is lowered by about one degree centigrade ad the body cells are quietly engaged in getting rid of waste materials that have accumulated during the active part of the day.
How many hours should healthy person sleep? The number of sleeping hours needed varies with individuals. An average adult needs 7 to 9 hours of sleep. Boys and girls of 15 years of age need about 10 ours sleep each night. It is wise to form the habit of going to bed at the same time each night.
Insomnia is the condition in which a person has difficulty in falling asleep. Such sleeplessness is often associated with pain, but worry can also keep a person awake. A dark, quiet room that is wee-ventilated and cool is good for sound sleep.