Chapter 6 Stem cells
How are the billions of cells in our bodies made? In plants and animals, there are cells capable of producing every type of cell the organism will need from birth to death. Once an organism begins to mature, other cells are required to produce the range of specialized cells needed for a functioning organ or tissue. Such cells are known as stem cells. As technology has developed and the micro-dissection of tissue became possible, it was evident that most, if not all, organs and tissues in the body have their own stem cells which are capable of dividing and differentiating into mature functional cells. In some ways, stem cells can be imagined as blank canvases with many hidden cellular pictures already imprinted on them. Different combinations of proteins (growth factors) or other stimuli such as fats or sugars that touch the cell can stimulate division and allow the daughter cells to take on changed characteristics. In this chapter we look briefly at the types of stem cell and where they come from.
