RJA #8b: Evaluation Check

http://playersyrita.blogspot.com/2010/03/rja-7a-evaluation-of-sources.html#comments-form

http://jaronhuff.blogspot.com/2010/03/rja-7a-evaluation-of-sources.html#comment-form

RJA #8a: Quotation, Paraphrase, and Summary

Stem cells are distinguished from other cell types by two important characteristics. First, they are unspecialized cells capable of renewing themselves through cell division, sometimes after long periods of inactivity. Second, under certain physiologic or experimental conditions, they can be induced to become tissue- or organ-specific cells with special functions. In some organs, such as the gut and bone marrow, stem cells regularly divide to repair and replace worn out or damaged tissues. In other organs, however, such as the pancreas and the heart, stem cells only divide under special conditions.

http://stemcells.nih.gov/info/basics/basics1.asp

In Stem Cell Information from the National Institutes of Health (2009), two important characteristics are given that distinguish stem cells from other types of cells. The first characteristic of stem cells was that they are, “unspecialized cells capable of renewing themselves through cell division, . . . [and] second, under [particular] conditions, they can be induced to become tissue- or organ- specific cells with special functions.” When tissue becomes worn out or damaged, especially in the human gut or in the bone marrow, stem cells, if administered for repair of these problems, regularly divide. However, they only divide under special conditions, if used for the repair of the pancreas or the heart.

There are two major differences which set stem cells apart from other types of cells. First of all they are able to reconstruct themselves by going through a process of mitosis, and secondly they are, under particular conditions, able to reconstruct themselves to replace specific tissue and organs in the body. In some areas of the body the stem cells can repair and replace old or injured organs such as in the bone marrow or the human gut. Whereas, in other organs of the body, such as the heart or the pancreas, they can multiply only under specific circumstances.

Two main differences that set stem cells apart from other cells are first, being able to restore themselves through cell division and secondly, under particular conditions they are able to become organ specific cells that can perform organ specific functions. For example, cells transplanted for use in the human gut or bone marrow can help rebuild worn out or injured tissue. When used for the heart or pancreas, they are capable of dividing only under particular circumstances.