Types Of Stem Cells And Their Medical Uses Biology Essay

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A stem cell is an undifferentiated cell found in the developing embryos of all multicellular organisms. They have the ability to turn into any type of cell. Stem cells can also be found in adults but do not have the same versatility that embryotic stem cells have. Stem cells mostly remain in bone marrow in an adult's body. Stem cells are almost like seeds that your body uses to repair itself after an injury but not all injuries are repairable by your body itself. However, certain types of stem cells work to repair any type of tissue in the human body.

Currently adult stem cells are being used to treat human diseases. One example is bone marrow transplants to treat patients with leukemia. Although useful, adult stem cells do not have the same potential as embryotic cells have. Researchers have found that embryotic cells could possibly treat diseases such as Parkinson's, cancer, and spinal cord injuries. This makes embryonic stem cells much more valuable but there is also more controversy surrounding these kinds of stem cells.

Victims of spinal injuries are in unfortunate circumstances. In most cases there is little to no chance of recovery. This is because adult nerve cells do not divide or heal like other cells in the body. Every cell within an adult body is specialized. This means that there is a specific cell for each type of tissue in the body. Some examples of these tissues are: muscle, skeletal, skin, and nerve tissue. When a tissue is damaged, the cells of that tissue are able to repair themselves. This is true for all tissues except for nerve tissue. Stem cells have the ability to repair this problem.

A stem cell is the cell from which all other types of cells arise from. It is unspecialized but can be made into any of the 220 specialized cells found within the body. This is known as the pluripotency of the cell. They also have the ability to reproduce themselves many times over.

There are many types of stem cells. Embryonic stem cells can be found on a fetus, embryo, or an umbilical cord. They can form into any kind of cell in the human body. Adult stem cells are found in the tissues of infants, children, and adults. They can only form cells that are similar to the organs they belong to though, such as heart, brain kidney, and bones. The last type of stem cell is called an induced pluripotent stem cell. These are adult stem cells that have been altered experimentally so that they behave as embryotic stem cells.

Embryonic cells can be obtained in two different ways. The first is called in vitro, which is where you fertilize an egg cell outside of the body and then the fertilized egg is returned to the owner or extra are frozen for later studies. The second way is called therapeutic cloning, which is where a scientist would take a fertilized eggs nucleus and then replace it with another patient's nucleus within the fertilized egg. If stem cells are used in this way, there is a smaller chance that the patient's body will reject the stem cell. Once the stem cells are obtained they are placed in a nutrient rich substanvce and allowed to divide. The growths of all these undifferentiated cells are known as a stem cell lines. Stem cell lines are used in laboratory studies and therapies.

Adult stem cells can be found in many different types of tissues, but come in small numbers. There are about 10 stem cells to every 1,000,000 surrounding cells. They also look like the surrounding cells so scientists had to find a way to tell them apart from the other cells. Scientists identify and then isolate adult stem cells by tagging them with fluorescent molecules that attach to the receptors of proteins on the stem cells. Then when they are put under fluorescent lighting, they light up making it easy to tell them apart. These adult stem cells can be grown into stem cell lines like the embryonic stem cells after they are harvested.

Induced Pluripotent stem cells (IPSC's) were recently discovered in 2006. "Scientists reprogrammed differentiated cells so that they reverted back to a stem cell." They used a virus to deliver genetic information to the differentiated cell which caused the cell to become similar to an embryonic stem cell. From there, these cells could be divided into stem cell lines.

In order for scientists to treat diseases with stem cells, they must first establish stem cell lines, which scientists have recently found a way to do just that. Next, scientists need to be able to turn on specific genes inside the cell. The cell will then be differentiated into any type of cell desired. So far though, this process of activating an undifferentiated cell into any desired type of cell has yet to be discovered, and further research is needed to understand this process fully. But once this is figured out, scientists believe stem cells could be used for a variety of purposes. Some examples could be: Drug testing using human grown cells, repairing a patient's heart by stimulating stem cells to differentiate into heart cells etc. This could save many people's lives and give those born with deformities the possibility of living a normal life. But there are two sides to this.

Many people do not know much about stem cells besides the fact the stem cells come from developing embryos and with such little knowledge about stem cells, there is a lot of arguments about whether the use of stem cells should be permitted or not. With all of the things stem cell might be able to do for humans, there is a huge upside to learning more about stem cells. But from some people's points of view, it is not morally correct and should be outlawed. Stem cell research has become one of the biggest issues including scientific and religious communities around the world. The stem cell controversy is a debate centered only on the creation, usage, and destruction of human embryos. Usually, this controversy focuses on embryonic stem cells only. But as stated above, not all stem cell research involves the creation, usage and destruction of human embryos. For example, adult stem cells or induced pluripotent stem cells, do not involve creating, using or destroying human embryos, and is much less controversial.

However, most people do not know this. The majority of people think only about aborted fetuses when they hear about stem cells. The biggest question surrounding all of this controversy is, when does life begin? A religion such as the Catholic religion is against abortion because they believe that a fetus is a living person and by aborting it, you are taking away life. In a sense, they would be playing the part of God. Either way, to harvest an embryo's stem cells, scientists must destroy it. Pro-life supporters say, "That the use of adult stem cells from sources such as umbilical cord blood has consistently produced more promising results than the use of embryonic stem cells." They say adult stem cell research may be able to make greater advances if less money was used to fund embryonic stem cell research .This means the "pro-life" supporters are only against embryonic stem cell use and not the use of other types of stem cells

People that are for the use of stem cells argue that Embryos are not the same as human life. They say they are still incapable of surviving outside the womb (they only have the potential for life). "More than a third of zygotes do not implant after conception." So far more embryos are lost just by chance than are proposed to be used for embryonic stem cell research and treatments.

Some people say that embryos are not humans, believing that the life of Humans only begins when the heartbeat develops, which is during the 5th week of pregnancy, or when the brain begins developing activity, which has been detected at 54 days after conception. Embryonic stem cells are much more useful for treating injuries and we have already discovered how to use these kinds of stem cells

Blastocysts are a cluster of human cells that have not differentiated into distinct organs or tissues, making cells in the inner cell mass no more "human" than a skin cell.

The use of stem cells could also eliminate animal testing. It could also results in more accurate results, and less time and money wasted. They can be used for better and more advanced drug development.

Enduced stem cells are made with your own DNA. This creates a smaller chance that your body will reject the cells. Also, all stem cells do not come from developing embryos there are several different ways to obtain stem cells. The human body also regenerates cells with stem cells that do not normally repair or divide giving doctors the ability to heal injuries that have never been able to be repaired before. There is nothing else that we know of that is capable of doing what stem cells do.


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