有大神帮忙看看这篇文章大概讲了什么

有大神帮忙看看这篇文章大概讲了什么Now you are sitting in a garden reading a book.As the sun goes in and the breeze begins to blow,your skin gets cooler.The nerves which end in the skin notice this,and they send little electrical message about it.These are rather like telegraph messages.The messages (they are called nerve impulses)go from the skin,along the nerves to the spinal cord (脊髓).From there they pass up the spinal cord to the brain.When they arrive at the brain you have the feeling of being cold.Of course,the message travels very,very quickly from the skin to the brain.In your brain the never message cause some very complicated things to happen.They cause you to think.You think how cold you are and how you can get warm again.You decide that the best thing to do is to put your coat on.As soon as you decide to put your coat on,more nerve messages begin.This time they go in the other direction.They start in the brain,go down the spinal cord,and then out along the nerves.Instead of going to the skin,however,these messages go to muscles.When they arrive there,the muscles grow shorter-they contract.It is these contractions which make your body move in the right way to put your coat on again.