Layers of the Epidermis

Anatomy Exam 2

Basement membrane

• ECM layer

• Separates dermis from epidermis

Stratum basale

• Deepest epidermis layer

• Single layer of cells attached to basement membrane by hemidesmosomes

• Contains keratinocyte stem cells that divide and make new keratinocytes

• Contains melanocytes (produce melanin pigment)

Stratum spinosum

• 8–10 layers of keratinocytes

• Cells start flattening and make keratin protein as they move upward

Stratum granulosum

• 2–5 layers of flattened cells

• Cells begin to die in this layer

Stratum lucidum

• 3–5 layers of dead, transparent cells

• Only in thick skin (palms, soles)

• Absent in most thin skin

Stratum corneum

• 25+ layers of dead, flat squamous cells with keratin

• Prevents water loss

• Protects against abrasion

Come Lets Get Sun Burnt

corneum, lucid, granulosum, spinosum, basale

(all w stratum in front, from superficial to deepest)