Stem cells in the human body have a unique ability to renew themselves and give rise to the more specialized cell types that do the work of the body. Stem cells remain unspecialized until a signal from the body tells them to develop into specific cells of the body like a heart, nerve, or skin cell.
For years, researchers have been studying the unique characteristics of stem cells. The first stem cells studied by researchers were derived from adult tissues and, more recently, scientific breakthroughs have enabled research on stem cells that are removed from one of the earliest human cellular formations, the blastocyst.
What is a stem cell?
All stem cells, no matter their source, are unspecialized cells that give rise to more specialized cells. Stem cells can become one of more than 200 specialized cells in the body. They serve as the body's repair system by renewing themselves and replenishing more specialized cells in the body.
What do stem cells look like under the microscope?
Early human stem cells
How many types of stem cells are there?
The easiest way to categorize stem cells is by dividing them into two types: mature and early. Mature stem cells are found in specific mature body tissues as well as the umbilical cord and placenta after birth. Early stem cells, often called embryonic stem cells, are found in the inner cell mass of a blastocyst after approximately five days of development. See the below tables for more details on the characteristics of mature and early stem cells.
What are the advantages and disadvantages of mature and early human stem cells?
We still have a great deal to learn about both mature and early human stem cells and their potential for treating and hopefully curing disease. Both have distinct advantages and disadvantages associated with them and each offer important insight into how cells rejuvenate the body and cause disease. See the below table for more information: