Have you ever asked yourself these questions?
- Should I breathe now?
- Is the amount of the blood that my heart pumps sufficient?
- Which of my cells and organs require how much energy?
- When should my stomach start digesting the food I've eaten?
- Is the intensity of the light entering my eye in due proportion?
- Which muscles should I contract in order to move my arm?
- These questions sound odd, don't they?
That is because we never ask ourselves such questions. What's more, most of us are not even aware of the continuous performance of these processes. Our bodies perform all these processes automatically. And it uses the network of nerves to do this. This network is formed by the union of trillions of nerve cells, which you can see in these pages. We may compare this network of nerves, which reaches every corner of our body, to a motorway, as seen in the picture. Thanks to this network, the cells in our brain are linked to the muscle cells in our feet, and all body cells communicate with each other. Yet, our nervous system has a much more comprehensive system than kilometres of motorways, which have many crossroads and separate carriageways for vehicles travelling in opposite directions. Just as vehicles move from one place to another on motorways, electrical nerve impulses are transmitted along the network of nerves in our body. These impulses convey messages from one region to another. These impulses move in your body much faster than you can imagine. An electrical stimulus sets out from your brain, for instance, when you want to flex your arm. During this complicated journey, the stimulus first stops by the spinal cord. Thence it proceeds towards the organ concerned, to which the message should be conveyed. Your arm muscle contracts as a whole and you bend your arm at the elbow. This series of actions takes place in a mere thousandth of a second. Considering that it takes approximately a second to slowly close and reopen your eyes, one can better understand how short a thousandth of a second is. Similarly, stimuli are sent from the entire body to the brain via the nerves. From every single part of your body messages are sent to your brain continuously and at an amazing speed. So you can talk, laugh, run, taste the flavour of ice cream, play with your dog... all these processes occur without interruption; you perform the act immediately as you think about. You see the object right at the moment you look at it, you hear the words right at the moment they are uttered, and perceive whether an object is hot or cold right at the moment you touch it. All these are thanks to the perfect harmony between your brain and nervous system. Indeed, nerve impulses are active in your body at this exact moment too. Nerves in your fingertips are sending messages to your brain regarding the weight of this book that you are holding in your hand, so that you lift the book with a force suited to its weight. In the meantime, stimuli are sent from your eyes, nose, ears, feet and many other parts of your body to your brain as well. Your brain evaluates these incoming stimuli and sends relevant responses to the concerned parts of your body, which act according to these responses. Now let's recall all of these actions. Many processes occur within your body simultaneously. You read a book while at the same time you hear sounds from the external world, feel the soft fur of your cat as it passes between your legs, taste the flavour of the fruit juice you drink, your heart keeps beating and many other actions take place in your body. What would happen if you were to control all of these for a few seconds? Surely you would not be able to control all at the same time. However, thanks to the perfect creation of Allah, your brain and other parts of your body operate jointly and execute all these tasks without needing any intervention of yours. All kinds of information are transmitted from the body to the brain in the form of stimuli, which need to be interpreted. Only then can you perceive the softness of your dog's fur, the coolness of the wind, the flavour of the peach juice, the smell of the fried potatoes. Well then, do you think it is possible for your brain, which is a piece of flesh weighing not more than 1.5 kilos, to fulfil all these by itself? Of course not. Thanks to the splendid creation of Allah, your brain can carry out all these processes at the same time. ou would blink your eyes if a friend of yours approached you silently and clapped his hands suddenly when you had not noticed his or her coming. There is not another option, because this is a reflex. A reflex is an immediate involuntary response. The reason why it is immediate is that stimuli are not transmitted to the brain in such cases and the required response is received directly from the spinal cord. This is a significant gift that Allah created for us because, thanks to such reflexes, we are protected from many dangers. For instance, you can remove your hand immediately when you touch a hot glass. The reflex is a security mechanism that Allah created for the protection of our bodies. With the inspiration of Allah, nerve stimuli proceed in your body at a speed of approximately 9 kilometres (6 miles) in a second and so you are protected against many dangers.
No comments:
Post a Comment