An element is a pure substance that is made from a single type of atom. Elements are the building blocks for all the rest of the matter in the world. Examples of elements include iron, oxygen, hydrogen, gold, and helium.
Since the initial discovery that the adult brain contains stem cells that generate new neurons, an important question in neurobiology has been whether or not this adult neurogenesis is functionally important.
What are adult stem cells? Adult stem cells (often called somatic stem cells) are found in many organs and tissues of the body. Adult stem cells extracted from the bone marrow of patients or compatible donors are used routinely in treating diseases such as leukaemia. Umbilical cord blood, extracted from the umbilical cord and placenta when a baby is born, is a rich source of adult stem cells.