Our body's ability to regenerate
Few children nowadays will have witnessed this themselves, but older people may at some point have seen a lizard cutting off its own tail to escape from danger. The lizard seems to think nothing of leaving behind a part of its own body as it flees. Surprising as it is that the lizard snips off its own tail, more surprising still is the fact that the lizard's body will simply grow another one. The missing body part, which represents no small part of the entire lizard body, will proceed to grow back. In the world of biology, this phenomenon is referred to as "regeneration", which means that the body reverts to its original state.
It goes without saying that we humans will by no means grow a new foot or hand if we have lost an appendage. Even fingers, ear, or noses will not grow back. Unfortunately, our appendages do not grow back like lizards' tails. How wonderful it would be if parts of our body could be newly "regenerated" one after another! Injured or lost parts of our bodies could be completely restored. It would be an easy matter to completely cure loss of an arm in a traffic accident, severe burns that cover the entire body, or a foot badly fractured during a soccer game. But in actuality, our bodies are not that conveniently constructed.
Arms and feet may not grow back, but we still do observe "regeneration" in the human body. For example, if you fall down and skin your knee, it will bleed a lot at first. Then a scab will form, and when it is completely healed, it will look just like it did before. We can say that the skin has "regenerated" to its original form.
However, if the injury is a very large one, the skin will not grow back the way it was before, and a large scar may remain. In this case, we do not call the process "regeneration". Please think of "regeneration" as strictly meaning to return to the original form. When the injury is not that large, it does not take a long time to heal, and it returns to normal without leaving a scar - that is what we mean by "regeneration".
There are only very limited situations in which parts of our bodies will "regenerate". However, this "regeneration" is essential to our continued survival. Our "regeneration" is not as dramatic as a lizard's, but human beings' more limited ability to "regenerate" the body is also very important.
We would now like to discuss the theme of "regenerative medicine". As you read on, we hope to inspire a little interest and wonder at our body's amazing abilities of "regeneration".
