Adult Stem Cells: From Bench-Top to Bedside

Abstract

Endogenous populations of adult precursor cells have been identifi ed in 13 species of animals, including humans. Adult precursor cells can be divided into two general categories based on particular characteristics. These two categories are stem cells and progenitor cells. The adult stem cell populations consist of totipotent stem cells, pluripotent stem cells, ectodermal stem cells, mesenchymal stem cells, endodermal stem cells, surface ectodermal stem cells, neural ectodermal stem cells, neural crest stem cells, somitic mesenchymal stem cells, intermediate mesenchymal stem cells, lateral plate mesenchymal stem cells, endodermal stem cells and their respective intermediary transitional stem cells. The progenitor cell populations consist of multipotent, tripotent,