What are the different types of stem cells?

What are the different types of stem cells?

Embryonic stem cells

During the early stages of embryonic development the cells remain relatively undifferentiated (immature) and appear to possess the ability to become, or differentiate, into almost any tissue within the body. For example, cells taken from one section of an embryo that might have become part of the eye can be transferred into another section of the embryo and could develop into blood, muscle, nerve, or liver cells.

Cells in the early embryonic stage are totipotent (see above) and can differentiate to become any type of body cell. After about seven days, the zygote forms a structure known as a blastocyst, which contains a mass of cells that eventually become the fetus, as well as trophoblastic tissue that eventually becomes the placenta. If cells are taken from the blastocyst at this stage, they are known as pluripotent, meaning that they have the capacity to become many different types of human cell. Cells at this stage are often referred to as blastocyst embryonic stem cells. When any type of embryonic stem cells are grown in culture in the laboratory, they can divide and grow indefinitely. These cells are then known as embryonic stem cell lines.