Why do we get tired?
Tiredness in fact can be considered as poisoning. Working muscle is making milk acid. If we move this acid away from the tired muscle, it’ll be able to work again immediately!
We “poison ourselves” with milk acid whole day. There are other matters produced by our organism known as “toxins of tiredness”. Blood conveys them all organs, that is why not only one muscle, but also whole body, especially brain, feels tired.
Scientists have made a very interesting experiment with weariness. It turned out, that, if make a dog to work to tire out, until she sleeps because of tiredness, and then give another dog the first-dog blood transfusion, this dog will immediately become “tired” and sleep. But if give tired sleeping dog a blood of normal dog transfusion, the tiredness will disappear!
But tiredness is not only chemical, it is also biological process. We can’t just “take weariness off” – cells of organism need some relaxation. “Tired” nerve cells of brain need recharging, joints need rebuilding expended grease. And we need sleep for energy recharging.
But there is an interesting and very important moment in the process of relaxation. Person, who is tired of hard working at table for many hours, may not want to lie down and relax. He will like better to go for a walk. You will never make children to sleep pr have a rest after school; they want to run and play.
The reason is that if a certain part of body (for example, brain, eyes, arms or legs) is tired, the best method to return activity to this part is to liven up other parts of body! In point of fact, we can rest using active work. Activity strengthens breathing, intensifies blood circulation, stimulates gland working, as a result waste products remove from tired organ more quickly. But, if you are exhausted to the highest degree, it’ll be better to go to sleep.
What is pain?
Have you ever wanted not to feel pain? As a matter of fact we have to thank the destiny that we are able to do it (feel pain). Pain – is our saver. If you could not feel tooth pain, you would hurt yourself too much and too often. You could not know what is harmful – that is very bad, because that is why you could not know are you healthy or not.
Do you know there is an illness, which makes a person not to feel pain? Such people injure themselves very often – they burn, hurt, prick themselves, pain does not let them know they have to be more careful.
It is strange science still can’t explain exactly what is pain and its origin.
They think it is obliged by its origin to free (useless) nerve endings on skin. These endings feel something but pain appears only in case the energy they feel is too strong.
In a very hot thing molecules move very fast, that is why we feel pain touching it. Nerve endings are usually called “pain points”. There are nearly three million pain points on our skin where we can feel pain.
Pain can be very different – scald pain, cut pain, bite pain, etc. It is a combination of feelings like high temperature, pressure and other.
Some people understand what is pain and why it is needed. I think that such people can be sportsmen, people who work with medicine, scientists, etc.
Sportsmen know what is a real tire and pain. When you run for a long time you come home very weary. And the next day you can’t do anything because everything is pain to you: it hurts to sit, it hurts to stand, to go, to lay, to do anything. Your muscles are very tired, but when pain finishes, they will become stronger.
Vorobtsova Alexandra,
School 130.