Using human stem cells
Find out where stem cells come from and how they are used in humans and plants
Stem cells are undifferentiated cellA stem cell that has not developed adaptations specific to its function.. There are two types of stem cells:
Embryonic stem cells
Each of us began our lives when our father's sperm fertilised our mother's egg. At this point we were one embryonic stem cell. At this stage this cell could turn into any of the two hundred or so cells types that make up a human. For this reason, embryonic stem cells are essential for new life, but also extremely valuable in medical research.
Embryonic stem cells can divide to produce new cells, which can then divide into different cell types. They therefore have the potential to be transplanted into patients to treat medical conditions and diseaseIllness affecting plants and animals.. They could be used to replace cells that have been damaged or destroyed, eg:
- in Type 1 diabetesA serious disease in which the body is unable to regulate blood sugar.
- in cases of multiple sclerosisA disease which affects the brain and spinal cord and can make movement and communication difficult., which can lead to paralysisThe loss of muscle function in part of the body.
- in cases of spinal cordThe part of central nervous system of a mammal which runs inside its backbone or brainThe organ of the central nervous system of mammals where vital functions are coordinated injury, that have led to paralysis
Embryonic stem cells can differentiate into a wider range of cell types, but are difficult to obtain. The best source is the five-day-old embryo. These are often left over embryos from IVFThe letters stand for 'in vitro fertilisation'. This involves bringing the sperm and the egg together to create an embryo, which is placed into the woman's womb to increase the chance of giving birth.. This is an ethical issue which people may have strong feelings or opinions on due to religious or moral reasons.
Adult stem cells
Adult stem cells are present in developed organisms which no longer have embryonic stem cells. They are found in bone marrow, brain, muscle, skin and heart. However, they are not as useful for medical research as they will only differentiate into a narrower range of cell types. Bone marrow transplants are an example of adult stem cell transplant. Bone marrow cells will differentiate into different types of blood cell, but not any other type of cell. Bone marrow transplants are carried out:
- in cases of blood cell cancerA disease caused by normal cells changing so that they grow and divide in an uncontrolled way. The uncontrolled growth causes a lump called a tumour to form. such as leukaemia and lymphoma
- when blood cells have been destroyed by cancer treatment.
Learn more about stem cells with Dr Alex Lathbridge.
Listen to the full series on 大象传媒 Sounds.
Discover how cells differ in plants and animals and why they're really useful for scientists. Listen to the full series on 大象传媒 Sounds.