There are actually many types of stem cells. Embryonic stem cells come from an embryo that is 3 to 5 days old. These cells are undifferentiated and can become every single type of cell in the body, and are thus called “pluripotent.” There are other types of stem cells in the human body. Adult stem cells, or semi differentiated cells, reside in almost every tissue and organ in adult humans and are responsible for dividing and replenishing the local cell populations, and are called “multipotent.” As we age this stem cell division and replenishment happens less and less efficiently. We all have adult stem cells of varying degrees all over our bodies. An unborn baby’s umbilical cord is full of multipotent stem cells; our bone marrow has adult stem cells; and yes, hair follicle bulbs from your head also have adult stem cells.
