the.com/epidermis
The body's bouncer: the outermost skin layer deciding what gets in and what stays out.
means The thin, waterproof top layer of your skin, sitting above the dermis and shielding everything beneath it.
from From Greek epi, meaning upon, plus derma, meaning skin — literally the layer upon the skin, named by anatomists who liked to keep things blunt.
All deadIts surface is entirely dead, flattened cells.
Total refreshRenews itself roughly every four weeks.
No bloodHas no blood vessels of its own.
Dust sourceShed flakes make up much household dust.