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.
Differentiation of Keratinocytes: Keratinocyte stem cells reside in the basal layer of the epidermis, which is the lowest layer of the stratified epithelia. These cells divide to give rise to transient amplifying cells which divide further, and differentiate, as they move upwards in the epidermis.quamous keratinocytes are also found in the mucosa of the mouth and esophagus, as well as the corneal, conjunctival, and genital epithelia. These cells are responsible for forming tight junctions with the nerves of the skin. They also keep Langerhans cells of the epidermis, and lymphocytes of the dermis, in place.