A human development starts with just a single cell – the fertilized egg. This cell divides to produce two daughter cells. These daughter cells divide and their daughters divide again and so on. There are many steps needed to form a baby from the fertilized egg and from baby to an adult body. In this way, different types of cells must be made. The cell, which is involved in this process, is called as stem cells.
Stem cells can be defined as a cell, which are found in most organisms. These cells can regenerate for longer periods through cell division and it can develop into cells with specific functions. Stem cells are the potency cells, from which all the body cells are matured. It also gives rise to different cells like brain, nerve, pancreatic and heart cells.
Structure of Stem Cells
Below you could see characteristics of stem cells
- They are unspecialized cells.
- They are self-renewable cells, with the ability of dividing continuously for long periods of time.
- They are pluripotent cells with the ability of developing into different kinds of cells or tissues.
- They help in repairing the damaged cells in all living organisms.They have an ability to differentiate into other cells.
Stem cells possess two general properties-: Self renewable and potency.
Potency is defined as the cells, which has a potential to differentiate into different cell types. There are three main types of potency of stem cells.
- Totipotent stem cells: These cells develop during sexual reproduction when male and female gametes fuse during fertilization to form a zygote. Each cell can develop into a new individual, e.g.: zygote cells.
- Pluripotent stem cells: These cells have an ability to differentiate into several different types of cells, e.g.: embryonic stem cells and fetal stem cells.
- Multipotent stem cells: These cells have an ability to differentiate into a limited number of specialized cell types, e.g.: heart cells, blood cells, umbilical cord stem cells and adult stem cells.
Below you types of stem cells
- Embryonic stem cells: They are pluripotent stem cells. It comes from a five to six-day-old embryo. These stem cells have the capacity to develop to any types of cell in human body.
- Embryonic germ cells: The cells, which are found in specific part of the fetus that normally develops into mature gametes.
- Adult stem cells: They are specialized cells, which are found in different organs and tissues. These adult cells remain inactive for longer period of time until they receive an instruction by other parts of the body for a need of more cells. As these stem cells play an important role in replenish dying cells and regenerate damaged tissues.
- In the year 2007, a new stem cell has been discovered and was named as induced stem cell.
Stem cell technology is a promising area for research. They are used to repair or to replace the damaged organs and to cure several diseases. Stem cell technologies are also used to cure other disease like brain damage, acute leukaemia, chronic leukaemia, etc. This technology is also useful in replacing damaged tissue, to study the human development, testing gene therapy methods and for testing of new drugs.
Applications of stem cell technology in curing diseases.
Spinal cord injuries: The stem cells are first collected from a patient’s bone marrow and then implanted back into the body. These re-injected stem cells have the ability of developing into different kinds of cells and are capable of regenerating damaged tissue.
Tooth implanting: The stem cells, collected from a patient are cultured in the lab by turning into the tooth bud. Later on implanted into the patient’s gums. This implantation was quite similar to the original growth of a tooth.
Deafness: The embryonic stem cells are used and are succeeding in the re-growth of cochlea sensory hair cells
Baldness: The stem cells are also present in the human hair follicles. According to some scientist’s research, these stem cells can be used in treating baldness by hair multiplication method. The existing hair follicle stem cells are cultured in the laboratory and then implanted the new hair follicle into the scalp.
Heart disease: Adult stem cells are injected into the heart’s arteries. This treatment is believed to improve the cardiac functions.
Stem cell technology used in generating neural, muscle and blood cells.