optic disc, the small blind spot on the surface of the retina, located about 3 mm to the nasal side of the macula. It is the point where the fibers of the retina leave the eye and become part of the optic nerve.
Adult stem cells are found in many organs and tissues, including the skin. In fact, human skin is the largest repository of adult stem cells in the body. Skin stem cells reside in the basal layer of the epidermis where they remain dormant until they are activated by tissue injury or disease. 1.
Discovered in the 1960s, blood stem cells (haematopoietic stem cells) were the first stem cells to ever be discovered. Blood stem cells primarily reside in bone marrow and make all the cells found in blood, including cells important for the immune system. Transplants of blood stem cells have become widely used to treat diseases such as leukaemia, anaemia and autoimmune diseases.