Treating damage to the nervous system - Higher
Another term for a nerve cell that is specialised to transmit electrical impulses. are nerve cells that carry electrical Electrical signals that travel along the nerve fibre from one end of the nerve cell to the other. around the body. This allows the body to respond to Any change in the environment that can be detected by receptors in an organism..
The brain and spinal cord are part of the Central Nervous System (brain and spinal cord).. Any damage to the brain or spinal cord can seriously affect the body's ability to coordinate signals in response to stimuli.
The nervous system can be damaged by injury or through disease. For example, a car crash could cause a back injury that affects the spinal cord, causing The loss of muscle function in part of the body., or someone might develop A disease that causes motor neurons to stop functioning correctly, leading to a wide range of symptoms including the inability to control muscles. where signals can no longer be sent along motor neurons effectively.
Potential use of stem cells
When neurons have When an unspecialised cell becomes a more specialised cell type. during the development of an organism they cannot divide again. This means they are not capable of A type of cell division which produces daughter cells identical to the parent., and no new neurons can be made from existing ones. This means that damage to the nervous system can be difficult or even impossible to treat.
Scientists are carrying out research into the use of A cell found in foetuses, embryos and some adult tissues that can give rise to a wide range of other cells. to replace damaged cells in the nervous system. Stem cells can divide to produce new cells, which can differentiate into new cell types. They could be used to replace cells or tissues that have been damaged or destroyed in cases of The part of central nervous system of a mammal which runs inside its backbone or The organ of the central nervous system of mammals where vital functions are coordinated injury.
The stem cells used could be:
- A type of stem cell found in the embryo, capable of dividing into almost any cell type.
- A type of stem cell found in specific locations in adults. Adult stem cells can only differentiate into a limited number of related cell types.
Transplanting stem cells
Embryonic stem cells have to be taken form an embryo, which is usually destroyed in the process. Adult stem cell Surgical procedure in which a tissue or organ is replaced. use a patient's own stem cells. The cells are genetically identical to the patient's cells and so are not rejected by the patient's immune system.
Therapeutic cloning
Using cloning technology for medicinal purposes. One example is to use a person's DNA to clone one of their organs for use in transplanting. could produce stem cells with the same genetic make-up as the patient. The technique involves the transfer of the nucleus from a body cell of the patient, to a human donor The female reproductive cell. whose The nucleus controls what happens inside the cell. Chromosomes are structures found in the nucleus of most cells. The plural of nucleus is nuclei. has been removed.
Stem cells produced in this way could be transferred to the patient. Although human stem cells have been produced in this way, and used in research, there is no Information or material that shows something is true. that they have been used to treat anyone yet.
Benefits and risks of stem cell treatments
There are clinical, Relating to right and wrong, eg ethical companies are often ones that act in a responsible way. and social issues with use of stem cells.
Clinical issues
- There is no guarantee how successful these therapies will be, for example, the use of stem cells in replacing nerve cells lost in Parkinson's disease patients still requires much more research.
- It is difficult to find suitable stem cell donors.
- A random and spontaneous change in the structure of a gene, chromosome or number of chromosomes. have been observed in stem cells which might cause them to behave like cancer cells.
- Stem cells can sometimes be contaminated with viruses which would be transferred to a patient.
Ethical issues
- A source of embryonic stem cells is unused embryos produced by in vitro fertilisation (IVF) - at what stage of its development should an embryo be regarded as, and treated as a person?
- For therapeutic Using cloning technology for medicinal purposes. One example is to use a person's DNA to clone one of their organs for use in transplanting., is it right to create embryos for therapy, and destroy them in the process?
- Embryos could come to be viewed as a commodity, and not as an embryo that could develop into a person.
Social issues
- Educating the public about what stem cells can and can't do, is important.
- Whether the benefits of stem cell use outweigh the risks.
- Much of the research is being carried out by commercial clinics, so reported successes are not subject to A process where expert scientists check research written by others before it is published in a scientific journal.. Patients could be exploited by paying for expensive treatments and being given false hope of a cure, as stem cell therapies are only in their developmental stages.
More guides on this topic
- How do substances get into, out of and around our bodies?
- How does the nervous system help us respond? - OCR 21st Century
- Why do we need to maintain a constant internal environment?
- What role do hormones play in human reproduction? - OCR 21st Century
- Sample exam questions - the human body - staying alive