pigmentary epithelium, pigmented epithelium. that made of cells containing granules of pigment. posterior epithelium. the single layer of epithelial cells on the back of the cornea, between stroma and aqueous humour; the corneal endothelium.retinal pigment epithelium. see retina.sense epithelium, sensory epithelium. see neuroepithelium (1).he single layer of epithelial cells on the back of the cornea, between stroma and aqueous humour; the corneal endothelium. retinal pigment epithelium. see retina. sense epithelium, sensory epithelium. see neuroepithelium (1).
Since at least the mid-19th century, doctors have known that silver or silver compounds can cause some areas of the skin and other body tissues to turn grey or blue-grey. Argyria occurs in people who ingest or inhale
When you put a zinc surface on Steel material you definitely have an activated skin. Dip your part in a 1,5 % HNO 3 and look at the Surface. When you see a reaction then you have reaction stains. You must passivate the surface with yellow or transparent chromate and you have no more black stains.