B1 - Stem Cells in medicine

• Stem cells


  Cells that can divide by mitosis to produce more cells and can differentiate into different types of specialized cells
• Types of stem cells

  • Embryonic stem cells (found in early embryo, can differentiate into any cell type)
  • Adult stem cells (found in bone marrow, can only differentiate into blood cells)
• Conditions treated with stem cells

  • Diabetes (damaged pancreas cells)
  • Paralysis (damaged nerve cells)
  • Sickle cell anemia (misshapen red blood cells)
• Using stem cells to treat conditions

  1. Extract embryonic stem cells

  2. Grow in lab

  3. Stimulate differentiation into required cell type

  4. Inject into patient to replace faulty cells
• Drawbacks of using embryonic stem cells

  • Limited supply
  • Ethical issues around using embryos
  • Risk of rejection by patient's immune system
• Adult stem cells


  Can be taken from patient, won't cause rejection, but can only differentiate into blood cells
• Embryos used for research are usually unwanted from fertility clinics and would otherwise be destroyed
• Embryonic stem cell research is legal but tightly controlled in the UK