For all of you who assumed these pictures are of the outer layer of our skin, you are incorrect!
It's really our toe and finger nails.
The pictures you're looking at are the nail plates, which are the hard outer coverings of the nail. It is covering our nail bed which is the delicate area underneath the keratin which is covered in glands and capillaries. Keratin is added (nails grow) at the proximal end which is actually the only living area of the nail (but be sure to also prevent the proximal end from growing too much! I sometimes grow my toenails to the point where it looks too homologous with an eagle's talon).