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.
The superficial layer of skin. It is composed of squamous epithelium cells. These are flat scale-like cells that are arranged in layers, called stratified squamous epithelium. The many layers of the epidermis create a barrier to infection.The epidermis does not have a blood supply, so it is dependent on the deeper layers of skin for nourishment. However, the deepest epidermis layer is called the basal layer. These cells are alive and constantly dividing.he many layers of the epidermis create a barrier to infection. The epidermis does not have a blood supply, so it is dependent on the deeper layers of skin for nourishment. However, the deepest epidermis layer is called the basal layer.