Every system of the human body has tasks it has to do and they all must work in cooperation with each other and there's where nerves step in.
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Nerves are part of our body that carries signals between our brain and the rest of the body and they are like electrical wires in our home: without them nothing will work. They are made of many fibers named axons and those axons are grouped into bundles. Bundles are protected with layers of tissue, just like an electrical wire has a plastic around its metal core.
The first group of nerves, motor nerves, carry signals between the brain and muscles and because of them our muscles move. The second group, sensory nerves, carry signals between the brain and other parts of the body. Those nerves are used to signal internal and external events such as pain, pressure or temperature.
When a nerve is damaged it can't send and receive signals and its part of the body is cut off from the rest of the body. If fibers inside nerves are cut and insulation is not, the end of the fiber farthest from the brain will die and the end closest to the brain will not die and it may heal after some time. Under the healthy insulation new fibers may start to grow up to the point where the nerve is whole and functioning again.
How do you know that your nerve is damaged? Fortunately, that's easy to diagnose. Since nerves transmit signals that manifest as pain, the strong pain may be the first sign of nerve damage. For example, you reach over the table for salt and feel a strong pain in your ribs: your nerve just became stuck between the ribs. You are working with a computer mouse for days and you feel that pain in hand that doesn't go away: the nerve in your wrist is damaged.
And if you feel tingling for a long time, say hours, that's the sign that your nerves are maybe damaged. If you fall on your hand and you can't control it any more - the nerves are damaged. In general, we may say that strong pain or the absence of feelings are signs of damaged nerve.
Along with mechanical reasons, there are some medical conditions that can cause nerve damages. They are: stroke, diabetes, cancer, poisoning with lead, mercury or other heavy metals, infections of the brain or spinal cord, excessive consumption of vitamin B6, AIDS, excessive consumption of alcohol, and some other conditions.
Doctors can help in cases of serious nerve damage with a surgical procedure. But there's one more problem: the surgery is usually possible when the nerve has been sharply cut. If there is a greater gap between two ends it may not be possible to sew them together. In that case a small piece of donor nerve is used to bridge the gap between the two nerves and then the nerve will regenerate across that bridge.
Three to four weeks after the surgery the patient can start with therapy, and nerves are closely monitored with a simple procedure: when the injured nerve is tapped, the patient will feel something like an electric tingling. That's the signal that the nerve is regenerating.
If the damage occurred in the central nervous system, the situation is much worse. Contrary to the peripheral nervous system, the central system can't fix its damaged nerves: nerves are trying to grow but they can't do that in full and they stay damaged. That's the reason why, for example, damage to the lower spinal column leads to paraplegia.
Now, how long does it take for a damaged nerve to recover? That depends on the level of damage, but in general we may say that the damaged fibre inside its protective envelope grows slowly, about one inch per month. That means that even the nerve with a minor injury may take several months to be restored completely. There is one more bad news: when the new nerve becomes functional it doesn't fit perfectly to the old one and that means that some functions are lost forever. ■