Stem cells are undifferentiated cells capable of dividing indefinitely and differentiating into all kinds of tissue. There are two main categories of stem cells:
Adult stem cells are subdivided into hematopoietic; which able to differentiate into all kinds of blood cells (red cells, platelets, lymphocytes, etc.) and mesenchymal, which are able to differentiate into tissues such as cartilage, tendon, bone, skin, etc. .
Mesenchymal stem cells are those used in both human medicine and veterinary medicine for the treatment of tissue regeneration and repair.