Stem cells are a certain type of cells that are classified by their ability to differentiate into different tissues. They are also self- renewing cells. There are three different types of stem cells that have been discovered (Iwamori, Iwamori, & Matzuk M., 2012). The types are embryonic, adult, and induced pluripotent stem cells. Research is currently being done to analyze the potential medical benefits of stem cells. There are also many different ethical questions surrounding stem cells (Shahid & Irshad, 2012).
When one is looking at normal tissue it is very rare to find stem cells. To obtain stem cells the tissue must be purified extensively. Theoretically all tissues originally comes from stem cells. With this thinking one would assume that stem cells would be present in all tissues. This however is not always the case. The most successful isolation of stem cells from normal tissues have been found in bone marrow. These cells are called haematopoietic stem cells. Haematopoietic stem cells are often referred to as HSCs. HSCs is currently being used to treat blood and immune system diseases, but more current research is being done to test if HSCs can be used to regenerate other types of tissues. There has been some research to support that other tissues have arisen from HSCs (Reya, Morrison, Clarke, & Weissman, 2001).
Stem cell research is so important because of the possibilities stem cells open up. It is the idea of being able to harness a basic undifferentiated self-renewing cell, and then differentiate it into what the human body needs. Science isn’t quite to that point yet, but with further research it is a definite possibility. The way that stem cells work is that they respond to signals that come from surrounding cells. Those surrounding cells are already specialized cells (Shahid & Irshad, 2012). According to (Iwamori, Iwamori, & Matzuk M., 2012) the process of stem cell differentiation begins when neighboring germ cells are connected through an intercellular bridge.
There are three different types of stem cells. These types are embryonic, adult, and induced pluripotent stem cells. Pluripotent stem cells are commonly referred to as iPSCs (Shahid & Irshad, 2012). Embryonic stem cells come from a blastocyst which is from a three to five day old embryo. Embryonic stem cells come from eggs that have been fertilized in vitro with the intention to be implanted into a woman’s uterus. The cells are grown in a culture for about four days than one cell is implanted. The rest of the cells are either destroyed, or used for embryonic research. The embryonic stem cell gives rise to everything in the developing organism (Macherla & Murahari, 2012).
Adult stem cells are stem cells that come from fully developed organisms. They are most commonly found in bone marrow, and more recently have been found in brain, and cardiac tissue. Those adult stem cells could be used to regrow needed tissues without some of the ethical concerns...