Cornea case study
1. The cornea controls and focuses light in the eye. The cornea is responsible for about 75 percent of the eye's focusing power. As light enter the eye, the cornea refracts it onto the retina to help the eye focus on objects.
2. A cornea can be prepared after sustaining damage. If the cornea is scratched, healthy cells quickly heal the scratch before it gets an infection. If the damage is serious, the person can receive a cornea transplant. Also, scientists have discovered a new way to repair the cornea by using stem cells.
3. A cornea transplant is when a section of a damaged cornea is removed and replaced with a healthy cornea from a donor. Only about 20% of the transplants are rejected.
4. Some cornea transplants fail because the new cornea is rejected by the body. The body has security mechanisms that reject unfamiliar tissue. They can also fail because the eye lacks the necessary stem cells to maintain a healthy cornea.
5. Stem cells are cells that have the potential to divide and create new stem cells or become a different cell type with a specialized function. A totipotent stem cell is a cell that can become any type of human cell. Pluripotent stem cells can become any cell, but cannot give rise to an entire organism. As they divide, they become more specialized. Multipotent stem cells can become a limited range of cells within a tissue type. Unipotent stem cells can only become one cell type.
6. Embryonic stem cells are pluripotent. Adult stem cells are multipotent and rarer.
7. Limbus stem cells are necessary to reconstruct the cornea. They are important because they replace the epithelial cells that age and wear away. It is difficult to identify and obtain the necessary amount of stem cells.
8. Stem cells repair the cornea when it is damaged and provide a clear surface over the cornea. The corneal stem cells work everyday to renew the cornea. Limbus stem cells renew the cornea when it is seriously damaged.
9. A major concern with adult
2. A cornea can be prepared after sustaining damage. If the cornea is scratched, healthy cells quickly heal the scratch before it gets an infection. If the damage is serious, the person can receive a cornea transplant. Also, scientists have discovered a new way to repair the cornea by using stem cells.
3. A cornea transplant is when a section of a damaged cornea is removed and replaced with a healthy cornea from a donor. Only about 20% of the transplants are rejected.
4. Some cornea transplants fail because the new cornea is rejected by the body. The body has security mechanisms that reject unfamiliar tissue. They can also fail because the eye lacks the necessary stem cells to maintain a healthy cornea.
5. Stem cells are cells that have the potential to divide and create new stem cells or become a different cell type with a specialized function. A totipotent stem cell is a cell that can become any type of human cell. Pluripotent stem cells can become any cell, but cannot give rise to an entire organism. As they divide, they become more specialized. Multipotent stem cells can become a limited range of cells within a tissue type. Unipotent stem cells can only become one cell type.
6. Embryonic stem cells are pluripotent. Adult stem cells are multipotent and rarer.
7. Limbus stem cells are necessary to reconstruct the cornea. They are important because they replace the epithelial cells that age and wear away. It is difficult to identify and obtain the necessary amount of stem cells.
8. Stem cells repair the cornea when it is damaged and provide a clear surface over the cornea. The corneal stem cells work everyday to renew the cornea. Limbus stem cells renew the cornea when it is seriously damaged.
9. A major concern with adult