| Term | Definition |
| stratum corneum | outermost layer |
| stratum lucidum | between stratum corneum and stratum granulosum on soles and palms |
| stratum granulosum | beneath the stratum corneum |
| stratum spinosum | beneath the stratum granolosum |
| stratum basale | deepest layer |
| stratum corneum | many layers of keratinized, dead epithelial cells that are flattened and nonnucleated |
| stratum lucidum | cells appear clear; nuclei, organelles, and cell memebranes are no longer visible |
| stratum granulosum | 3 to 5 layers of flattened granular cells that contain shrunken fibers of keratin and shriveled nuclei |
| stratum spinosum | many layers of cells with centrally located, large, oval nuclei and developing ribers of keratin cells becoming flattened |
| stratum basale | a single row of cuboidal or columnar cells that divide and grow; this layer also includes melanocytes |