What are stem cells?

Stem cells are defined as undifferentiated cells that have the unique ability to develop into different cell types. This characteristic is fundamental to their role in both normal physiological processes and medical applications. Unlike specialized cells, such as muscle or nerve cells, stem cells do not have a predetermined function and can give rise to a variety of cell types depending on the signals they receive from their environment.

The versatility of stem cells is crucial for growth, healing, and regeneration in biological systems, which allows them to play a significant role in developmental biology and regenerative medicine. They can be classified into embryonic and adult stem cells, with embryonic stem cells having the capacity to differentiate into nearly all cell types, while adult stem cells are generally limited to differentiating into a narrower range of cell types specific to the tissue or organ they reside in.

While stem cells are present in embryos, stating they are only found there overlooks the presence of adult stem cells in various tissues throughout the body. Additionally, they should not be confused with specialized cells that serve distinct functions or cells involved in signal transmission in the nervous system. Understanding stem cells' undifferentiated nature and potential for differentiation is key to their importance in both research and therapeutic contexts.