Epidermis

Tuesday, November 6, 2012

The epidermis is the exterior layer of squamous, overlapping, epithelial cells which constitute tha skin. The epidermis has no blood vessels and consists of five sub-layers of cells: 1) stratum basale, which is the deepest layer that is constantly producing new cells which move upward, replacing the older dead epithelial cell on the surface; 2) stratum spinosum, which is composed of prickle cells; 3) stratum granulosum, composed of granular cells containing lamellar granules; 4) stratum lucidum, which is a translucid dead cell layer; 5) stratum corneum, which consists of flat dead cells, filled with keratin, that form the outer skin layer.