Stem Cells

In the mid 1980's stem cells were discovered in mice. Stem cells are undifferentiated cells that can be used to form specialized cells. Three types of human stem cells exist, depending on the development of the person.

Embryonic stem (ES) cells originate from the inner cell of the human embryo during the early stages of human development. The early stage of development is about 5 days. Nearly one hundred embryonic stem cells can be in an embryo for about a day before they become specialized and develop. Because these cells are still embryonic, they hold the potential to grow into any kind of tissue.

Another type of human stem cell is the embryonic germ (EG) cell. These cells are obtained within five to nine weeks of the development stage. They originate from primordial germline cells in fetal tissue. Because these cells are taken later on in the developmental period than ES cells, they appear to be more limited in term of their specialization.

The final type of human stem cell is the adult stem cell. These cells can be cultivated from an individual of any age, past the embryonic stage. These cells are much more specialized than ES and EG cells. They have been found all over the human body: including bone marrow, skin, blood vessels, blood, brain, and even the umbilical cord. In the bone marrow, hematopoietic stem cells can develop into different types of blood cells.

Stem cells are very important to future medical research, especially embryonic stem cells. These stem cells have the ability to grow into any type of tissue in the human body. This would allow for organs to be grown, reducing the need for people to be placed on long transplant lists. Instead of waiting for a heart to become available upon the death of a donor, hearts can be grown in a lab using stem cells. By using stem cells, doctors would not have to worry about biocompatibility. The organs could be grown using stem cells from that patient.

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