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 blood becomes depleted of oxygen, it changes from bright red to darker in colour, and it's this that makes the skin and lips look blue. In darker-skinned people, the blue tinge may be easier to spot in the lips, gums and around the eyes. The medical name for this blue tinge is cyanosis.