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
  • Adult stem cells
• Embryonic stem cells


  • Found in the early embryo
  • Can differentiate into any type of specialized cell
• Adult stem cells


  • Found in the bone marrow
  • Can only differentiate into different types of blood cells
• Many conditions are due to faulty cells that are damaged or don't work properly
• Using stem cells to treat conditions

  1. Extract stem cells

  2. Grow them in a lab

  3. Stimulate them to differentiate into desired cell type

  4. Transplant into patient
• Conditions that could be treated with stem cells

  • Diabetes
  • Paralysis
  • Sickle cell anemia
• Drawbacks of using embryonic stem cells

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

  • Easy to obtain
  • No risk of rejection
  • Can only differentiate into blood cells
• Potential risks of using stem cells

  • Virus transmission
  • Tumor development
• Some people object to using embryonic stem cells on religious or moral grounds as they have the potential for human life
• Embryos used for research are usually unwanted ones from fertility clinics that would otherwise be destroyed
• Embryonic stem cell research is tightly regulated in the UK with strict rules for scientists to follow
• What is the problem with type 1 diabetes?

  The pancreas cells are damaged and no longer produce insulin, causing insulin deficiency.
• Paralysis


  When nerve cells are damaged, messages can no longer be sent to the muscles properly. This can lead to losing the ability to move some or all of your body.
• Give two drawbacks of using embryonic stem cells in stem cell therapy.

  The embryonic stem cells must come from embryos. These are in limited supply, and some people have ethical objections to it, as they think the embryos could have developed into a person.

  The cells could be rejected by the person's immune system as it would identify them as foreign.
• Which two of the options below are advantages of using adult stem cells rather than embryonic stem cells?

  1. Adult stem cells are taken from the patient so are not in limited supply
  2. Adult stem cells won't cause rejection as they're taken from the patient themselves
• Two risks of using stem cells in medicine

  1. The stem cells could be infected with a virus whilst in the laboratory, which could then infect the patient.
  2. As stem cells divide quickly, there is a chance they could divide uncontrollably once they've been transplanted, and then develop into a tumour.