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
This is due to oxygenated iron in the red blood cells. Deoxygenated â¦ blood is a darker shade of red, which can be seen during blood donation and when venous blood samples are taken. However, due to an optical effect caused by the way in which light penetrates through the skin, veins typically appear blue in color.