1. LAYERS OF THE EPIDERMIS Notes in Notebook for HW 11/17
FROM SUPERFICIAL TO DEEP:
Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum basale

4. STRATUM CORNEUM “horny layer” Outermost epidermal layer
Made up of 20 to 30 cell layers
Keratinization = cells gain keratin and are constantly sloughed off and replaced by new cells

5. STRATUM LUCIDUM Thin layer, but makes skin here thicker Clear, dead
keratinocytes
*Only found where skin is hairless
(palms and soles of feet)

6. STRATUM GRANULOSUM Many granules in cells
Some granules contain a waterproof lipid and others contain keratin
Upper portions are beginning to die here

7. STRATUM SPINOSUM “spiny layer” Cells appear spiky
Some cell division occurs in this layer
Receives some nourishment from the dermis (by diffusion of blood)

8. STRATUM BASALE One row of cells right above dermis
Cells constantly reproducing through cell division
Adequate blood supply from dermis
Melanocytes (pigment cells)
produce the pigment (MELANIN) in this layer