A stem cell is a cell in a living body with the potential to develop into different types of cells during the early stage. Most cells in a living organism are differentiated cells, meaning they are found in a specific organ and perform particular functions. Red blood cells, for example, are specifically designed to transport oxygen through the blood. Human beings start out as a single cell known as a zygote, which is a fertilized egg. The zygote undergoes cell division into two, then four, eight, sixteen, and so on. The cells begin to differentiate and specialize in specific functions in the body as the zygote develops. The cells that haven't acquired specific purpose are known as stem cells; they can replicate indefinitely unlike differentiated cells that begin to break down after replicating. Once a stem cell divides, it remains as a stem cell or turns into a differentiated cell. This makes them especially intriguing for scientific research.
Types of Stem Cells
There are two types of stem cells: embryonic and adult stem cells. Embryonic stem cells are derived from embryos developed through in vitro fertilization in a fertilization clinic. The fertilized eggs are then donated for research purpose with the consent of the donors. Embryonic stem cells develop into specialized cells as the embryo develops. Adult stem cells are found among differentiated cells in an organ or tissue. Their main functions are to repair and maintain the tissue. Unlike embryonic stem cells that are produced by the embryo, researchers are still trying to understand the source of adult stem cells.
Properties of Stem Cells
Stem cells have three distinct properties regardless of their source; they replicate and renew themselves infinitely, they are unspecialized, and they give rise to differentiated cells. Unlike a nerve cell, blood cells, or muscle cells, stem cells can proliferate. Research conducted in laboratories have revealed that stem cells can yield millions of unspecialized cells with the properties of the parent stem cell.
Stem Cell Research
The properties of stem cells make them excellent and intriguing candidates for research. The embryonic human stem cells provide information concerning the complex process that occurs during the development of life. The primary objective of the research is to understand how undifferentiated cells end up with specific functions. Human stem cells are used to test new drugs and observe how a human body would respond to the medication. Stem cells are also helping researchers study diseases such as cancer and diabetes and how they can be treated. The immediate potential application of stem cell research is the generation of tissues and cells that replace organs once destroyed or removed. A breakthrough would eliminate the dependency on organ transplant, but instead, patients would receive stem cells that would generate the organ. Preliminary research in rodents shows that transplanted stem cells from the bone marrow can generate heart muscle tissues and repair the heart. A bone marrow transplant is already being used as a treatment for some form of cancer in humans.